Publish YouTubeDL 1.4.5 and website on Gitea

.github/workflows/checks.yml

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+name: Check extension and helper
+on:
+  push:
+    branches: [main]
+    paths-ignore: ['site/**', 'docs/**', '*.md']
+  pull_request:
+  workflow_dispatch:
+permissions:
+  contents: read
+jobs:
+  check:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v7.0.1
+      - uses: actions/setup-node@v7.1.0
+        with:
+          node-version: '24'
+          cache: npm
+      - uses: actions/setup-python@v7.0.0
+        with:
+          python-version: '3.13'
+      - run: python -m pip install -r requirements.txt
+      - run: npm ci
+      - run: npm run check
+      - run: npm test
+      - run: python -m unittest discover -s tests -v
+      - run: python tools/build.py

.gitignore

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+.runtime/
+__pycache__/
+*.pyc
+test-artifacts/
+dist/
+node_modules/
+.build/
+.build-cache/
+.venv/
+extension/helper-installer.exe
+.env
+.env.*
+*.log

CONTRIBUTING.md

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+# Сборка и проверки правообладателя
+
+Этот документ описывает обслуживание официальной версии правообладателем и уполномоченными им лицами.
+Публикация инструкций не предоставляет права изменять, создавать самостоятельные форки
+или распространять новые версии собственного кода. Условия и исключения — в [LICENSE](LICENSE).
+Пользователь может собрать неизменённую официальную поставку для установки и использования по назначению.
+
+Исходники расширения — `extension/`, Native Messaging помощника — `host/`,
+установщика — `tools/setup.cs`, сайта — `site/`.
+Готовые EXE, приватный runtime, кеши, личная история и `node_modules` в Git не включаются.
+
+## Быстрые проверки
+
+Нужны Python 3.10+ и Node.js 22+. Для тестов помощника установите `requirements.txt`
+в отдельное виртуальное окружение. Не меняйте глобальное окружение пользователя.
+
+```powershell
+python -m venv .venv
+.\.venv\Scripts\python.exe -m pip install -r requirements.txt
+npm ci
+.\.venv\Scripts\python.exe -m unittest discover -s tests -v
+npm test
+npm run check
+python tools/build.py
+```
+
+`tools/build.py` собирает небольшой `dist/YouTubeDL-1.4.5.zip` без EXE.
+Для сборки расширения не требуется предварительно собирать помощник.
+
+## Браузерные проверки
+
+Нужен установленный Microsoft Edge в Windows; для `test:ui` можно задать `YTDL_TEST_BROWSER`.
+Скриншоты и отчёты сохраняются в игнорируемую папку `test-artifacts`.
+
+```powershell
+npm run test:ui
+npm run test:setup
+npm run test:thumbnails
+npm run test:motion
+npm run test:live-shorts
+npm run test:site
+```
+
+Проверки UI используют контролируемые браузерные API. `test:motion` и `test:live-shorts`
+загружают настоящее расширение в отдельный профиль Edge; последняя открывает живой YouTube.
+`test:site` проверяет сайт в браузере на широком и узком экране, ссылки скачивания, темы и навигацию.
+
+`npm run test:reconnect` использует отдельную установку и уникальное имя native host:
+проверяет install/remove/reinstall, разрывы портов и две открытые панели без перезагрузки.
+Ему нужен `dist/YouTubeDL-Helper-Setup.exe`.
+`test:browser` скачивает публичный тестовый ролик и проверяет NVENC через FFprobe.
+**`test:helper` удаляет и повторно устанавливает зарегистрированный помощник текущего пользователя**:
+запускайте только в подготовленной тестовой учётной записи Windows.
+`tests/offline-bundle.py`, `tests/component-update.py` и `tests/amd-fallback.py` проверяют автономность,
+обновления и отказ AMD с переходом на CPU. GPU-проверки зависят от реального оборудования.
+
+## Сборка помощника
+
+Нужны Windows x64, C# compiler .NET Framework и Python. Подготовка требует интернет,
+работает в `.build-cache` и `.build`, проверяет закреплённые SHA256.
+
+```powershell
+python tools/build_bundle.py --prepare
+# Повторная сборка из подготовленного комплекта:
+python tools/build_bundle.py
+```
+
+Версия помощника берётся из `host/common.py`, версия расширения — из `extension/manifest.json`.
+Не меняйте публичный `key` расширения: он закрепляет ID, разрешённый установленному native host.
+EXE самодостаточен; `install.ps1` / `install.cmd` предназначены для разработки с внешним Python.
+
+## Релизы и сайт
+
+- Публикуйте ZIP расширения, отдельный `YouTubeDL-Helper-Setup.exe`, манифест, лицензии/исходные материалы и `SHA256SUMS.txt` в релизах Gitea.
+- Перед выпуском обновите версии и ссылки в `INSTALL.md`, `README.md`, `site/index.html` и документации. Стабильное имя EXE позволяет использовать URL `/releases/download/vВЕРСИЯ/YouTubeDL-Helper-Setup.exe`.
+- Исходники статического сайта находятся в `site/` того же репозитория. Nginx публикует их по адресу https://git.lonarpgproxy.space/extention/youtubedl/; обновление выполняется из проверенного коммита main отдельным развёртыванием.
+- Для локального просмотра: `python -m http.server 4173 --directory site`, затем `http://127.0.0.1:4173`.
+- Графика и её промпты описаны в `docs/ASSETS.md`. Не добавляйте в маркетинговые скриншоты настоящие cookies, приватные ссылки или личные пути.
+
+Для подготовки исходников FFmpeg и его библиотек используйте закреплённую копию
+FFmpeg-Builds из архива исходных материалов релиза. На Linux с Docker выполните
+`./download.sh win64 gpl-shared`; параметры и скачиваемые ревизии заданы в сценариях этой копии.
+Проверяйте лицензии и доступность соответствующих исходников при замене стороннего runtime.
+
+Предложения улучшений и ошибки присылайте через Issues; для изменений собственного кода
+нужно предварительное письменное разрешение правообладателя. В bug report укажите версии ОС, браузера,
+расширения и помощника, действия для воспроизведения и текст ошибки без личных данных.

INSTALL.md

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+# Установка YouTubeDL
+
+Нужны **Windows 10/11 x64** и **Microsoft Edge или Google Chrome 120+**.
+Firefox, macOS, Linux и Windows ARM не входят в эту сборку.
+
+Скачивания доступны в [релизах проекта](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest).
+Помощник распространяется **отдельно**: внутри архива расширения EXE нет.
+
+1. Скачайте **YouTubeDL-1.4.5.zip** и распакуйте его в постоянную папку. Не удаляйте и не перемещайте её после установки.
+2. Откройте `edge://extensions` или `chrome://extensions`. Включите **Режим разработчика**, нажмите **Загрузить распакованное расширение** и выберите папку **extension** внутри распакованного архива.
+3. На странице релиза отдельно скачайте **YouTubeDL-Helper-Setup.exe**. Это автономный комплект: Python, yt-dlp, EJS, Node.js, FFmpeg и FFprobe уже внутри.
+4. Запустите EXE вручную и дождитесь окончания установки. Администратор и интернет для установки комплекта не требуются. Программы устанавливаются для текущего пользователя в `%LOCALAPPDATA%\YouTubeDL\Helper`.
+5. Обновите вкладку YouTube, откройте **⚙** рядом с кнопкой скачивания или значок расширения. Мастер первого запуска проверит помощник и предложит выбрать папку, качество и формат.
+6. Если меню было открыто во время установки, нажмите **Проверить подключение** в мастере или **Запустить** в обычном меню. Зелёный статус означает реальный ответ помощника. Перезагрузка страницы для переподключения не нужна.
+
+Загрузчик использует сохранённые параметры. Кнопка **Скачать** запускает загрузку, а **⚙** открывает настройки.
+На превью и в Shorts доступны эти же действия в виде значков.
+
+## Проверка скачанных файлов
+
+Скачивайте файлы из релизов `git.lonarpgproxy.space/OwnerLink/YouTubeDL`.
+Чтобы проверить целостность файла, сравните его SHA256 с `SHA256SUMS.txt` в том же релизе.
+
+```powershell
+Get-FileHash -Algorithm SHA256 -LiteralPath '.\YouTubeDL-Helper-Setup.exe'
+```
+
+## Обновления
+
+- **Расширение:** скачайте новый ZIP из Releases, распакуйте поверх прежней папки, нажмите кнопку перезагрузки на странице расширений и обновите вкладки YouTube. Автоматической установки ZIP нет.
+- **Сам помощник:** скачайте новый EXE из Releases и запустите его вручную. Кнопки установки и восстановления открывают страницу Releases.
+- **Обновление компонентов** проверяет официальные источники и обновляет Python в ветке 3.13, Node.js в ветке 24 LTS, yt-dlp с зависимостями, EJS и FFmpeg с FFprobe. Запустить его вручную можно кнопкой «Обновить компоненты». По умолчанию такая проверка выполняется раз в сутки, пока помощник работает, между операциями. Её можно выключить в меню. Нужен интернет.
+
+## Удаление
+
+Нажмите **Удалить** в меню помощника или удалите YouTubeDL Helper в установленных приложениях Windows,
+затем удалите расширение на странице управления браузера.
+Скачанные ролики и локальная история помощника сохраняются.
+Чтобы удалить и историю после удаления помощника, удалите `%LOCALAPPDATA%\YouTubeDL\Helper\data`.
+Настройки расширения удаляются вместе с расширением. Подробнее — [PRIVACY.md](PRIVACY.md).
+
+## Если что-то не работает
+
+| Симптом | Что проверить |
+| --- | --- |
+| Помощник не установлен | Скачан и запущен именно `YouTubeDL-Helper-Setup.exe`, а не только ZIP. Установка выполнена в том же пользователе Windows, где открыт браузер. |
+| Помощник не отвечает | Нажмите «Запустить». При повреждении комплекта скачайте EXE из Releases и переустановите. Не удаляйте `key` из manifest.json: ID расширения должен быть `ndnoeiaecgmjnjneekaeapeecmmjheli`. |
+| Нет кнопок на YouTube | Перезагрузите расширение, затем обновите вкладку. YouTube меняет разметку; приложите к issue адрес страницы, версии браузера и расширения. |
+| YouTube просит подтвердить вход | Откройте ролик в текущем профиле, пройдите проверку сайта. При необходимости включите «Использовать вход в YouTube» в меню и разрешите необязательный доступ к cookies. Это не гарантирует доступ к любому ролику. |
+| GPU недоступен | Проверьте драйвер, список проверенных кодеков и режим «Авто». В режиме «Авто» возможен переход на CPU. Принудительный GPU-режим сообщает об ошибке. |
+| Скачивание медленное | GPU ускоряет перекодирование видео; скорость сети и ограничения YouTube от видеокарты не зависят. |
+
+Не прикладывайте cookies, токены, личные ссылки и полные пути с именем пользователя к публичным обращениям.
+Сообщить об ошибке: [Задачи проекта](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/issues).
+
+## Диски и временные файлы
+
+В меню ⚙ поле «Сохранить в» задаёт папку готового файла. Поле «Рабочая папка для загрузки и обработки» задаёт место для скачанных дорожек и временных файлов FFmpeg. Оба поля допускают выбор папки на любом доступном диске. Если рабочая папка пуста, используется папка сохранения. Настройки действуют для следующих загрузок.
+
+При разных дисках результат сначала копируется во временную папку на диске сохранения, затем публикуется под итоговым именем. Прогресс копирования виден в уведомлении; частичный файл не появляется под готовым именем. При отмене помощник завершает группу процессов данной задачи и удаляет её временные папки.
+
+Для отдельной рабочей папки, подробного прогресса слияния и исправленной отмены установите помощник 1.3.2 и расширение 1.4.5. Обновление компонентов не заменяет программный код помощника; для этой версии запустите новый установщик помощника.
+
+## История и ошибки
+
+Кнопка **«История загрузок и ошибок»** под настройками открывает отдельную вкладку. Раздел **«Загрузки»** показывает завершённые и отменённые скачивания, дату, имя, размер и путь файла; **«Показать файл»** открывает его в проводнике через помощник. Раздел **«Ошибки»** содержит сообщения о сбоях скачивания, получения качества, установки и обновления компонентов.
+
+История хранится локально в браузере: до 30 последних операций. Просмотр работает и без помощника, новые результаты появляются без перезагрузки страницы. Текущие операции и прогресс остаются в настройках и уведомлениях.
+
+## Совместимость версий
+
+В настройках и мастере первого запуска отображаются версии расширения и помощника. Расширение 1.4.5 поддерживает помощник 1.3.2. При старом помощнике появится кнопка «Обновить помощник», при более новом помощнике или устаревшем расширении — «Обновить расширение». Пока совместимость не подтверждена, новая загрузка не запускается.
+
+После установки помощника нажмите «Проверить»: статус изменится без перезагрузки страницы. После замены файлов расширения нажмите «Обновить» на странице расширений браузера и перезагрузите вкладку YouTube. Обновление компонентов обновляет инструменты внутри комплекта и не заменяет само расширение или код помощника.
+
+## Когда работает видеокарта
+
+Видеокарта используется при перекодировании видео. В режиме «Авто» совместимое видео сохраняется без перекодирования: уведомление показывает «Подготовка файла · без перекодирования». Слияние дорожек и финализация файла также не требуют видеокодировщика.
+
+Для проверки выберите поддерживаемый кодек, например H.264 или HEVC, и «NVIDIA NVENC» в поле ускорения. При обработке появится «Перекодирование · NVIDIA NVENC». В диспетчере задач откройте «Производительность» → GPU и выберите график Video Encode / «Кодирование видео». Если обрабатывается только звук, уведомление покажет «Обработка аудио · CPU».

LICENSE

@@ -0,0 +1,76 @@
+ОГРАНИЧЕННАЯ ПОЛЬЗОВАТЕЛЬСКАЯ ЛИЦЕНЗИЯ YOUTUBEDL
+Версия 1.0, 8 октября 2026 года
+
+Copyright (c) 2026 OwnerLink. Все права сохранены.
+Правообладатель: OwnerLink (https://git.lonarpgproxy.space/OwnerLink).
+
+1. ОБЛАСТЬ ДЕЙСТВИЯ
+
+Эта лицензия относится к собственным файлам проекта YouTubeDL, предоставляемым
+с этой лицензией: самому браузерному расширению, собственному коду локального
+помощника, установщика и инструментов, документации, сайту и оригинальным
+материалам оформления (далее — «Программа»).
+Исключения для сторонних компонентов и прав платформы
+указаны в разделе 4 и имеют приоритет над ограничениями раздела 3.
+
+2. РАЗРЕШЁННОЕ ИСПОЛЬЗОВАНИЕ
+
+Правообладатель предоставляет бесплатное, неисключительное, непередаваемое
+разрешение скачивать официальную поставку, устанавливать и запускать Программу
+на принадлежащих пользователю или администрируемых им компьютерах только
+по назначению: получать доступные пользователю видео и аудио с YouTube,
+выбирать дорожки и параметры, объединять, конвертировать и сохранять файлы
+при наличии права сохранять соответствующий контент.
+
+Разрешены необходимые для этого установочные и резервные копии, сборка
+неизменённой официальной поставки для собственного использования, настройка
+через штатные средства, установка официальных обновлений и удаление Программы.
+Это не предоставляет права изменять собственные файлы кода и дизайна.
+
+3. ЗАПРЕТЫ
+
+Без предварительного письменного разрешения правообладателя запрещается:
+
+- изменять, адаптировать, переводить код или оформление Программы либо
+  создавать производные версии;
+- создавать и развивать самостоятельные форки, ветки разработки и проекты
+  на основе собственного кода Программы;
+- копировать или извлекать собственный код и оформление для других проектов;
+- распространять, перепубликовывать, предоставлять третьим лицам, продавать,
+  сдавать в аренду или сублицензировать Программу, её изменённые версии либо
+  существенные части, кроме копий, прямо разрешённых разделом 2;
+- удалять или заменять уведомления об авторстве, правообладателе и лицензии.
+
+Все права, прямо не предоставленные этой лицензией, сохранены за правообладателем.
+Для отдельного разрешения обращайтесь к OwnerLink через профиль Gitea проекта.
+
+4. ИСКЛЮЧЕНИЯ
+
+4.1. Python, Node.js, yt-dlp, EJS, FFmpeg, FFprobe и другие сторонние компоненты,
+их исходники и лицензионные тексты регулируются лицензиями их правообладателей.
+Эта лицензия не ограничивает предоставленные ими права, в том числе права
+на изменение, форки и распространение по GPL, MIT и другим лицензиям.
+Состав и сведения о лицензиях приведены в THIRD_PARTY.md и материалах релиза.
+
+4.2. Публикация репозитория на GitHub сопровождается правами, предусмотренными
+условиями GitHub. В частности, для публичных репозиториев GitHub предусматривает
+просмотр и создание копий через функцию fork внутри платформы. Эта лицензия
+не отменяет эти права и не является технической блокировкой функции fork.
+Ограничения раздела 3 действуют в части, не покрытой отдельно предоставленными
+правами платформы и применимого законодательства.
+Условия: https://docs.github.com/en/site-policy/github-terms/github-terms-of-service
+
+4.3. Права, которые применимое законодательство не позволяет ограничивать
+договором, сохраняются. Эта лицензия не предоставляет прав на чужой контент
+YouTube и не заменяет правила соответствующих сервисов.
+
+5. ГАРАНТИИ И ОТВЕТСТВЕННОСТЬ
+
+Программа предоставляется «как есть», без гарантий работоспособности,
+пригодности для определённой цели, постоянного доступа к YouTube или наличия
+конкретного качества и аппаратного ускорения. В пределах, допускаемых
+применимым законодательством, правообладатель не отвечает за убытки,
+потерю данных и другие последствия использования Программы.
+
+При нарушении условий этой лицензии предоставленное ею разрешение прекращается;
+это не прекращает права, отдельно сохраняемые разделом 4.

PRIVACY.md

@@ -0,0 +1,59 @@
+# Обработка данных
+
+Актуально для расширения **1.4.5** и помощника **1.3.2**. Исходники доступны для просмотра,
+условия использования собственного кода ограничены [лицензией](LICENSE).
+У проекта нет собственного сервера обработки видео, аккаунтов, телеметрии, рекламы или аналитики.
+Это не означает отсутствие обработки данных: необходимые сведения используются на вашем компьютере,
+а запросы к YouTube и источникам обновлений идут через интернет.
+
+## Какие данные используются
+
+| Данные | Для чего и где |
+| --- | --- |
+| Ссылка на выбранный ролик, ID, название, канал, доступные дорожки | Получение качества и скачивание. Расширение передаёт выбранную ссылку локальному помощнику через Native Messaging. Метаданные обрабатываются в памяти; завершённые операции попадают в локальную историю. |
+| Качество, формат, кодек, папка, своё имя файла, тема и состояние мастера | Сохранённые настройки в `chrome.storage.local` текущего профиля. Синхронизация через `storage.sync` не используется. |
+| История и состояние операций | Расширение сохраняет до 30 последних операций в `chrome.storage.local`: название, ссылку, состояние, результат, путь и текст ошибки при её наличии. Помощник отдельно сохраняет до 30 успешно завершённых загрузок в своей папке данных для истории и «Показать файл». Разработчику эти записи не отправляются. |
+| Название GPU, проверенные кодеки, версии компонентов | Проверка локального оборудования и программ, выбор рабочего режима конвертации и показ статуса. Не отправляются разработчику. |
+| Настройка и время проверки обновлений | Локальный `update-settings.json` помощника. По умолчанию автоматическое обновление включено. |
+| Cookies YouTube — только после согласия | Необязательная авторизация загрузчика в текущем профиле. Передаются локальному помощнику, затем используются yt-dlp в запросах к YouTube. Не пишутся в файлы cookies, настройки или историю; остаются в памяти на время обработки запроса. |
+
+Скачивание и обработка выполняются в выбранной рабочей папке, в подпапках `.ytdl-*`.
+При сохранении результата на другом диске временный файл создаётся также в папке сохранения.
+Помощник очищает их по окончании операции; после аварийного завершения остатки могут сохраниться.
+Готовые видео и аудио остаются там, куда вы указали.
+
+## Разрешения расширения
+
+| Разрешение | Назначение |
+| --- | --- |
+| `nativeMessaging` | Связь с установленным локальным помощником. Браузер запускает его по зарегистрированному имени; HTTP-сервер на локальном порту для этой связи не нужен. |
+| `storage` | Параметры, локальное состояние операций и мастера. |
+| `notifications` | Уведомления о ходе и результате операций. |
+| `activeTab` | Получение адреса активной вкладки по действию пользователя. |
+| Доступ к `www.youtube.com`, `m.youtube.com`, `music.youtube.com` | Кнопки и работа со ссылками YouTube. Скрипты кнопок запускаются на www/m; Music-ссылки можно открыть через окно расширения. |
+| **Необязательные** `cookies` и `https://*.youtube.com/*` | Включаются только кнопкой «Использовать вход в YouTube». Код выбирает cookies домена YouTube, включая HttpOnly, и не читает Google cookies, пароли или файлы профиля. |
+
+Chrome выдаёт разрешение `cookies` как браузерную возможность, а не отдельное разрешение на каждый cookie.
+В этой реализации область чтения дополнительно ограничена доменом YouTube в коде.
+Кнопка **Отключить** отзывает необязательное разрешение и прекращает передачу входа в новые операции.
+Уже начатая операция может завершить запрос с переданным ранее состоянием входа.
+
+## Кому идут сетевые запросы
+
+- **YouTube и используемые им медиасерверы:** ссылки, запросы метаданных и скачивания; при включённом входе — cookies YouTube. Эти сервисы видят ваш IP и обрабатывают запросы по своим правилам.
+- **Официальные источники компонентов:** `python.org`, `nodejs.org`, GitHub и его серверы релизов, `pypi.org` и `files.pythonhosted.org`. Запросы возникают при ручном или автоматическом обновлении. Передаются обычные сведения сетевого запроса, необходимые для скачивания; история роликов и cookies туда не отправляются.
+- **Сайт и Gitea проекта:** переходы к сайту, репозиторию, релизам и задачам на `git.lonarpgproxy.space`. Сервер сохраняет стандартные журналы запросов: IP, время, запрошенный адрес, статус ответа и User-Agent браузера. История загрузок видео, локальные пути и cookies YouTube туда не отправляются. Статический сайт не содержит счётчиков, внешних шрифтов, рекламных SDK или собственных cookies. Тема сайта сохраняется в `localStorage` браузера. Gitea использует cookies для собственных сеансов входа; они не относятся к сессии YouTube. Запросы к GitHub по-прежнему возможны при обновлении сторонних компонентов с их официальных источников.
+
+Установка первоначального EXE после скачивания работает без интернета. Само скачивание роликов требует интернет.
+Нет отдельного «облачного» сервиса YouTubeDL, куда отправляется ролик для конвертации.
+
+## Где хранятся данные и как их удалить
+
+Обычная установка: `%LOCALAPPDATA%\YouTubeDL\Helper`, пользовательские данные — подпапка `data`.
+При работе из исходников используется локальная `.runtime` проекта.
+Удаление помощника сохраняет скачанные файлы и историю. После удаления помощника можно удалить его `data`,
+если история тоже не нужна. Удаление расширения удаляет его локальные настройки в данном профиле браузера.
+Очищать скачанные файлы нужно в выбранной вами папке.
+
+Публичные задачи и вложения в Gitea проекта видны другим людям. Перед отправкой отчёта уберите cookies,
+токены, приватные ссылки и личные пути. Текст ошибки и скриншот не отправляются автоматически.

README.md

@@ -0,0 +1,117 @@
+<p align="center"><img src="site/assets/github-cover.png" alt="YouTubeDL — Видео. Звук. Ваш выбор." width="100%"></p>
+
+# YouTubeDL
+
+Скачивайте видео и Shorts с YouTube прямо из Edge или Chrome. Выберите качество,
+формат и папку один раз: **загрузчик** использует сохранённые настройки,
+а **⚙ рядом** открывает меню. Обработка и объединение дорожек выполняются на вашем компьютере.
+
+**[Сайт проекта](https://git.lonarpgproxy.space/extention/youtubedl/)** ·
+**[Скачать расширение и помощник](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest)** ·
+**[Инструкция](INSTALL.md)** · **[Обработка данных](PRIVACY.md)** ·
+**[Сообщить об ошибке](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/issues)**
+
+Windows 10/11 x64 · Microsoft Edge / Google Chrome 120+ · расширение **1.4.5** · помощник **1.3.2**.
+Расширение устанавливается распакованным, через режим разработчика. В магазинах браузеров пока не опубликовано.
+
+## Что умеет
+
+- **Кнопки там, где вы смотрите:** рядом с «Подписаться», на превью обычных видео, в полках Shorts и открытом Shorts-плеере.
+- **Видео со звуком, только видео или только аудио.** Раздельная звуковая дорожка автоматически скачивается и добавляется к видео.
+- **Выбор дорожек:** доступные разрешения, FPS, HDR и языки аудио. 4K/8K доступны, если есть у источника; разрешение искусственно не увеличивается.
+- **Форматы видео:** MP4, MKV, WebM. **Аудио:** M4A/AAC, MP3, Opus, FLAC, WAV. Исходный кодек или конвертация в H.264, HEVC, AV1, VP9 с учётом совместимости формата.
+- **Отдельные рабочая папка и папка сохранения**, в том числе на разных дисках. В рабочей папке скачиваются дорожки и выполняется обработка; готовый результат сохраняется в выбранную папку.
+- **Прогресс FFmpeg:** процент, обработанное время, записанные мегабайты, скорость и примерный остаток. Отмена завершает процессы только соответствующей задачи.
+- **Проверка совместимости версий:** расширение показывает свою версию и версию помощника. Если нужно обновить один из компонентов, сообщает какой и открывает страницу релизов.
+- **Своя папка и имя файла.** При совпадении имени добавляется `(1)`, `(2)` и т. д.; готовые файлы не перезаписываются.
+- **Две операции одновременно**, отмена, прогресс подготовки/скачивания/объединения/конвертации и «Показать файл».
+- **Отдельная страница истории:** вкладки «Загрузки» и «Ошибки», дата, имя, размер и путь готового файла. Кнопка в настройках открывает её в новой вкладке; история доступна без помощника и обновляется при завершении операций.
+- **Настройка при первом запуске**, адаптивная светлая/тёмная тема, уведомления с анимациями и поддержкой уменьшения движения.
+- **Реальная проверка помощника, компонентов и GPU**, ручное и автоматическое обновление встроенных компонентов.
+- **Необязательный вход в YouTube:** после отдельного согласия используется сессия текущего профиля браузера, без экспорта cookies в файл.
+
+<p align="center"><img src="site/assets/menu-dark.png" alt="Настройки YouTubeDL: качество, звук, формат и папка" width="440"></p>
+
+Скриншот показывает настоящий интерфейс с тестовыми метаданными.
+Возможности конкретного ролика определяет YouTube. Плейлисты, пакетное скачивание каналов,
+DRM-контент и гарантированный обход ограничений YouTube не заявляются.
+
+## Установка: два отдельных скачивания
+
+1. Откройте [последний релиз](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest), скачайте **YouTubeDL-1.4.5.zip** и распакуйте в постоянную папку.
+2. В `edge://extensions` или `chrome://extensions` включите **Режим разработчика**, нажмите **Загрузить распакованное расширение** и выберите папку **extension**.
+3. **Отдельно скачайте YouTubeDL-Helper-Setup.exe из того же релиза** и запустите его вручную. EXE не встроен в расширение: кнопка установки открывает страницу релизов.
+4. Обновите YouTube, откройте **⚙** и пройдите мастер. Выберите папку и параметры; зелёный статус подтверждает связь с помощником.
+
+Все компоненты уже находятся в EXE: Python, yt-dlp, EJS, Node.js, FFmpeg и FFprobe.
+Для установки после скачивания интернет не требуется. Администратор не нужен;
+комплект устанавливается в `%LOCALAPPDATA%\YouTubeDL\Helper` для текущего пользователя.
+Системный PATH и глобальные Python/Node.js не меняются.
+
+Контрольные суммы скачанных файлов можно сверить с `SHA256SUMS.txt` в том же релизе.
+Подробные шаги, обновление и удаление — в **[INSTALL.md](INSTALL.md)**.
+
+## Что даёт видеокарта
+
+YouTubeDL определяет оборудование Windows и проверяет доступность кодировщиков пробным запуском FFmpeg.
+Поддерживаются **NVIDIA NVENC** и **AMD AMF** для H.264, HEVC и AV1, если их поддерживает конкретная карта/драйвер.
+У GeForce RTX 20/30 аппаратное кодирование доступно для H.264 и HEVC; у RTX 40/50 — также для AV1. Возможности конкретной модели приведены в [матрице NVIDIA](https://developer.nvidia.com/video-encode-decode-support-matrix).
+Для AMD отдельно проверяется 10-битное кодирование HEVC/AV1. В «Авто» при необходимости используется CPU;
+принудительный режим сообщает об ошибке GPU.
+
+GPU ускоряет **перекодирование видео**, а не интернет. Совместимые дорожки копируются без перекодирования —
+это обычно самый быстрый вариант. Аудио и VP9 обрабатываются на CPU.
+Уведомление отдельно показывает слияние дорожек, подготовку файла без перекодирования, кодирование через NVIDIA NVENC/AMD AMF или CPU и финализацию файла. При проверке нагрузки в диспетчере задач откройте «Производительность» → GPU и выберите график **Video Encode / Кодирование видео**.
+HDR → H.264 без тонального преобразования отклоняется, чтобы не испортить цвета.
+FLAC/WAV не восстанавливают качество, уже потерянное в исходном аудио.
+
+NVENC проверен на **RTX 5080**. Поддержка AMD реализована, но успешное AMF-кодирование
+на физической AMD-карте пока не проверено: проверены выбор команд, отказ и переход на CPU.
+
+## Данные и приватность
+
+Нет аналитики, рекламы, телеметрии и сервера разработчика для обработки роликов.
+**Локально сохраняются** настройки и до 30 последних операций в браузере
+(включая названия, ссылки, статусы, пути файлов и ошибки). Помощник отдельно хранит
+до 30 успешно завершённых загрузок. Название GPU и версии компонентов проверяются для работы приложения.
+
+Cookies YouTube читаются **только после включения необязательного разрешения**.
+Передаются локальному помощнику через Native Messaging и используются в запросах yt-dlp к YouTube;
+не сохраняются в cookies-файл, настройки или историю. Google cookies, пароли и файлы профиля не читаются.
+Это чувствительные данные входа: включайте доступ только если он нужен. Его можно отозвать в меню.
+
+Сетевые запросы идут к YouTube/его медиасерверам и, при обновлениях, официальным источникам компонентов.
+Сайт, репозиторий и файлы релизов размещены на сервере проекта; при обращении к ним ведутся стандартные журналы запросов.
+Полный список данных, разрешений и способ удаления — **[PRIVACY.md](PRIVACY.md)**.
+
+## Обновления и удаление
+
+**Обновление компонентов** скачивает совместимые обновления Python, yt-dlp и его библиотек,
+EJS, Node.js и FFmpeg/FFprobe с официальных источников. Проверяются хеши, новый runtime проверяется
+до переключения; при ошибке остаётся прежний комплект. Автоматическая проверка включена по умолчанию:
+раз в сутки, пока помощник запущен, между операциями. Переключатель находится в меню помощника.
+Python остаётся в ветке 3.13, Node.js — в 24 LTS.
+
+Новую версию расширения установите из ZIP вручную. Новый код помощника — из отдельного EXE в Releases.
+Автообновление компонентов не заменяет эти два обновления.
+«Запустить» и «Проверить подключение» восстанавливают связь без перезагрузки страницы;
+открытое меню также проверяет её раз в 10 секунд.
+
+Удалить помощник можно в меню расширения или в приложениях Windows.
+Скачанные файлы и история сохраняются; при желании историю можно удалить отдельно.
+
+## Лицензии и разработка
+
+Новые поставки собственного кода — по **[ограниченной пользовательской лицензии](LICENSE)**:
+разрешены установка и использование по назначению. Изменение, самостоятельные форки,
+производные версии и распространение без письменного разрешения правообладателя запрещены,
+с учётом исключений лицензии. Это распространяется и на само расширение.
+
+Публичный репозиторий Gitea доступен для просмотра.
+
+Встроенные компоненты имеют собственные лицензии,
+включая **GPL v3 or later** у поставляемой сборки FFmpeg. Состав, источники и материалы релиза —
+**[THIRD_PARTY.md](THIRD_PARTY.md)**. Это независимый проект, не связанный с YouTube/Google, NVIDIA или AMD.
+
+Сборка, тесты и публикация сайта описаны в **[CONTRIBUTING.md](CONTRIBUTING.md)**.
+Используйте скачивание для контента, который вы вправе сохранять, с учётом правил источника.

THIRD_PARTY.md

@@ -0,0 +1,37 @@
+# Сторонние компоненты
+
+Лицензия в корне относится к собственным файлам YouTubeDL. Она разрешает использование
+по назначению и ограничивает изменение, самостоятельные форки и распространение.
+Встроенные компоненты помощника имеют **свои** лицензии; ограничения YouTubeDL
+не заменяют и не ограничивают их, в том числе права по GPL и MIT.
+Помощник вызывает FFmpeg отдельным процессом.
+
+Автономный комплект помощника 1.3.2:
+
+| Компонент | Версия | Проект / лицензия |
+| --- | --- | --- |
+| Python | 3.13.14, Windows embeddable x64 | [CPython](https://github.com/python/cpython/tree/v3.13.14), PSF и сопутствующие лицензии |
+| Node.js | 24.21.0 x64 | [Node.js](https://github.com/nodejs/node/tree/v24.21.0), MIT и лицензии встроенных библиотек |
+| yt-dlp | 2026.8.19 | [yt-dlp](https://github.com/yt-dlp/yt-dlp/tree/2026.08.19), Unlicense; зависимости лицензируются отдельно |
+| yt-dlp-ejs | 0.8.0 | [EJS](https://github.com/yt-dlp/ejs), лицензия пакета в его dist-info |
+| FFmpeg / FFprobe | N-127236-g17ec998942-20261007, shared win64 GPL | [FFmpeg](https://github.com/FFmpeg/FFmpeg/tree/17ec998942), GPL v3 or later для этой сборки; [сценарии FFmpeg-Builds](https://github.com/yt-dlp/FFmpeg-Builds) |
+
+Python-пакеты комплекта: brotli 1.2.0, certifi 2026.7.22, charset-normalizer 3.5.2,
+idna 3.20, mutagen 1.48.1, pycryptodomex 3.24.0, requests 2.34.2, urllib3 2.8.0,
+websockets 17.2. Их `METADATA` и лицензии находятся рядом с библиотеками в
+`runtime/python/Lib/site-packages/*.dist-info` установленного помощника.
+Тексты Python/Node.js/FFmpeg также входят в установленный комплект.
+
+В Releases приложены отдельный архив лицензий и исходных материалов,
+манифест исходных бинарных архивов с SHA256 и контрольные суммы публикуемых файлов.
+FFmpeg включает множество дополнительных библиотек с собственными лицензиями;
+точная конфигурация и ссылки на исходные материалы приведены в этом архиве.
+Для подготовки исходников зависимостей используются официальные сценарии
+`download.sh` проекта FFmpeg-Builds; инструкции приведены в архиве и [CONTRIBUTING.md](CONTRIBUTING.md).
+
+После обновления компонентов версии могут отличаться от этой таблицы.
+Измеренные версии смотрите в **Составе комплекта** расширения и `bundle.json` установленного помощника.
+Обновлённые wheels сохраняют лицензионные метаданные своих проектов.
+
+YouTube, Windows, Chrome, Edge, NVIDIA и AMD — названия соответствующих правообладателей.
+YouTubeDL — независимый проект; он не связан с YouTube/Google, NVIDIA или AMD.

docs/ASSETS.md

@@ -0,0 +1,18 @@
+# Графика проекта
+
+Готовые файлы находятся в `site/assets` и используются как в README, так и на сайте проекта.
+Растровые иллюстрации созданы встроенным **image_gen**; это декоративная графика, не скриншоты функций.
+Программная генерация/редактирование этих растровых иллюстраций не использовалась.
+
+- `hero.png`: исходная иллюстрация, 1774 × 887, без текста.
+- `github-cover.png`: обложка с названием и русским слоганом, 1774 × 887. Создана редактированием hero через image_gen.
+- `mark.svg`: векторная версия существующего знака скачивания; редактируется как SVG-код.
+- `menu-dark.png`, `menu-light.png`: настоящий рендерер расширения, снятый в отдельном Edge через `node tools/capture-site-ui.mjs`. Использован `tests/ui-fixture.js`, тестовые метаданные публичного ролика и условная папка `C:\Videos`. Реальные аккаунты и cookies не использовались.
+
+## Промпт hero
+
+Use case: a GitHub repository cover and website hero background for a real Windows browser extension called YouTubeDL. Asset type: landscape editorial product illustration, approximately 2:1 aspect ratio. Create a refined dark charcoal composition with a cyan and pale turquoise luminous download arrow as the focal point, a few translucent rounded video frames and subtle audio waveform threads converging into one small file object. Evoke downloading video and joining video with sound, without fake software screenshots. Art direction: precise, restrained, premium 3D/vector hybrid, soft studio lighting, matte graphite surfaces, crisp edges, generous negative space on the left for HTML headings. Focal objects mainly on the right. Colors: graphite #11161d, cyan #39bdeb, ice #91ece0, tiny warm white highlights. Avoid clutter, grids, big gradients behind text, stock photography, logos of YouTube/NVIDIA/AMD, GPU images, branding claims, people, watermarks. Absolutely no letters, numbers, captions or text anywhere. This is an original decorative visual, not a feature screenshot. Opaque background.
+
+## Промпт обложки
+
+Use case: GitHub README cover for the browser extension YouTubeDL. Edit this supplied original artwork into a clean wide 2:1 brand cover. Keep the graphite background and cyan video/audio/download illustration on the right, with generous breathing room. On the empty left place exactly one large, impeccably legible modern white sans-serif word: "YouTubeDL". Beneath it place exactly the short Russian subtitle "Видео. Звук. Ваш выбор." in smaller soft cyan type. Align both texts left, around the vertical center, safe margins at least 8% of width. No other text, logos, GPU references, version numbers, badges, watermarks or UI screenshots. Refined editorial typography, balanced hierarchy. Preserve the original illustration aesthetic and subdued dark background; do not fill the left with extra objects.

docs/RELEASE-1.4.1.md

@@ -0,0 +1,42 @@
+# YouTubeDL 1.4.1
+
+Исправлены формулировки в описании, инструкции, мастере и на сайте:
+загрузчик использует сохранённые настройки; обновление компонентов получает
+совместимые версии с официальных источников.
+
+Инструкция установки обновлена в репозитории, ZIP и на сайте;
+код расширения и помощника не менялся.
+
+## Лицензия собственных материалов
+
+Новые поставки сопровождаются ограниченной пользовательской лицензией,
+которая явно распространяется на само расширение. Разрешены установка и
+использование по назначению; изменение, самостоятельные форки, производные
+версии и распространение без письменного разрешения запрещены с учётом исключений.
+
+**Исключения:** сторонние компоненты сохраняют свои лицензии и права;
+условия публичного GitHub предусматривают форки внутри платформы.
+
+**[Лицензия](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/LICENSE)** ·
+**[Сторонние компоненты](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/THIRD_PARTY.md)**
+
+## Файлы и установка
+
+- **YouTubeDL-1.4.1.zip** — расширение и актуальные пользовательские документы, включая лицензию.
+- **YouTubeDL-Helper-Setup.exe** — отдельный помощник **1.3.0**, без изменений; все компоненты уже внутри.
+- **YouTubeDL-Helper-manifest.json** — версии и SHA256 помощника.
+- **YouTubeDL-ThirdParty-Materials.zip** — лицензии и исходные материалы, с актуальными пояснениями об области действия лицензии.
+- **SHA256SUMS.txt** — контрольные суммы файлов этого выпуска.
+
+**[Установка](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/INSTALL.md)** ·
+**[Сайт](https://git.lonarpgproxy.space/extention/youtubedl/)** ·
+**[Обработка данных](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/PRIVACY.md)**
+
+Windows 10/11 x64, Edge/Chrome 120+. Распакуйте ZIP, выберите папку `extension`
+в режиме разработчика браузера; скачайте и запустите помощник отдельно.
+Для обновления расширения замените файлы в его постоянной папке, перезагрузите
+расширение и обновите вкладки YouTube.
+
+Проверены сборка без EXE внутри ZIP и наличие лицензии в архиве,
+синтаксис и браузерный интерфейс, сайт в Edge на широком и узком экранах,
+контрольные суммы файлов релиза.

docs/RELEASE-1.4.5.md

@@ -0,0 +1,25 @@
+# YouTubeDL 1.4.5
+
+Расширение **1.4.5** и локальный помощник **1.3.2** для Windows 10/11 x64, Edge и Chrome 120+.
+
+- Скачивание видео и Shorts с сохранёнными настройками; отдельная кнопка настроек рядом.
+- Выбор качества, видеодорожек, языка звука, формата и кодека. Раздельный звук автоматически добавляется к видео.
+- Рабочая папка и папка сохранения могут находиться на разных дисках.
+- Уведомления показывают скачанные мегабайты, размер, скорость, этап обработки и прогресс FFmpeg. Отмена останавливает процессы соответствующей задачи.
+- Перекодирование через NVIDIA NVENC или AMD AMF при поддержке оборудования; совместимые дорожки копируются без перекодирования. NVIDIA проверена на RTX 5080; физической AMD-карты для проверки не было.
+- История открывается отдельной страницей с вкладками «Загрузки» и «Ошибки».
+- Мастер первого запуска, проверка совместимости версий расширения и помощника, переподключение без обновления YouTube.
+- Компоненты входят в помощник и обновляются с официальных источников.
+- Исходники, релизы и сайт проекта размещены в Gitea. Кнопки установки ведут к новой странице релизов.
+
+## Установка
+
+1. Скачайте **YouTubeDL-1.4.5.zip**, распакуйте и загрузите папку `extension` через режим разработчика в `edge://extensions` или `chrome://extensions`.
+2. Отдельно скачайте **YouTubeDL-Helper-Setup.exe** и запустите установщик. Все необходимые компоненты уже внутри; EXE не встроен в ZIP расширения.
+3. Откройте YouTube, нажмите ⚙ и пройдите мастер настройки.
+
+В релиз также включены манифест помощника, **YouTubeDL-ThirdParty-Materials.zip**, пользовательские документы и **SHA256SUMS.txt**.
+
+[Сайт](https://git.lonarpgproxy.space/extention/youtubedl/) · [Инструкция](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/INSTALL.md) · [Данные](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/PRIVACY.md) · [Лицензия](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/LICENSE) · [Сторонние компоненты](https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/THIRD_PARTY.md)
+
+Собственный код распространяется по ограниченной пользовательской лицензии: разрешено использование по назначению, изменения и распространение требуют письменного разрешения правообладателя. Сторонние компоненты сохраняют свои лицензии.

extension/background.js

@@ -0,0 +1,359 @@
+import { HOST_NAME, canonicalUrl, progressText, downloadSizeText, processingText, preferenceOptions, errorText, stabilizeDownloadSpeed, checkHelperCompatibility } from "./shared.js";
+import { readSession, SESSION_PERMISSION } from "./session.js";
+
+let nativePort = null;
+const pending = new Map();
+const clients = new Set();
+const jobContexts = new Map();
+let jobs = {};
+let helper = { status: "idle", message: "Помощник ещё не подключён.", hardware: null };
+let helperStartTask = null;
+const notificationTimes = new Map();
+const inspectionCache = new Map();
+const ready = chrome.storage.local.get(["jobs"]).then(saved => {
+  jobs = saved.jobs || {};
+  for (const [id, job] of Object.entries(jobs)) {
+    jobContexts.set(id, { tabId: job.tabId, title: job.title });
+    if (job.status === "running") {
+      jobs[id] = { ...job, status: "error", stage: "error", error: "Браузер или помощник был закрыт. Запустите загрузку снова." };
+    }
+  }
+});
+
+function broadcast(message) {
+  for (const port of clients) {
+    try { port.postMessage(message); } catch { clients.delete(port); }
+  }
+}
+function helperState(status, message, hardware = null, compatibility = null) {
+  helper = { status, message, hardware, compatibility, checkedAt: Date.now() };
+  broadcast({ event: "helper", helper });
+  return helper;
+}
+function saveJobs() {
+  const recent = Object.values(jobs).sort((a, b) => (b.createdAt || 0) - (a.createdAt || 0)).slice(0, 30);
+  jobs = Object.fromEntries(recent.map(job => [job.id, job]));
+  chrome.storage.local.set({ jobs: Object.fromEntries(recent.filter(job => !job.transient).map(job => [job.id, job])) });
+}
+function disconnect(error, status = "error") {
+  inspectionCache.clear();
+  nativePort = null;
+  helperState(status, error);
+  for (const [id, request] of pending) {
+    clearTimeout(request.timeout);
+    request.reject(new Error(error));
+    pending.delete(id);
+  }
+  for (const job of Object.values(jobs)) {
+    if (job.status === "running") onJob({ ...job, status: "error", stage: "error", error });
+  }
+}
+function connectHost() {
+  if (nativePort) return nativePort;
+  helperState("checking", "Запускаю и проверяю локальный помощник…");
+  nativePort = chrome.runtime.connectNative(HOST_NAME);
+  const port = nativePort;
+  port.onMessage.addListener(message => {
+    if (message.event === "job") { onJob(message.job); return; }
+    const request = pending.get(message.id);
+    if (!request) return;
+    pending.delete(message.id);
+    clearTimeout(request.timeout);
+    message.ok ? request.resolve(message.result) : request.reject(new Error(errorText(message.error || "Ошибка помощника")));
+  });
+  port.onDisconnect.addListener(() => {
+    const detail = chrome.runtime.lastError?.message;
+    if (nativePort === port) {
+      const missing = /host.*not found|not.*registered|cannot find.*host/i.test(detail || "");
+      disconnect(missing ? "Помощник не установлен. Скачайте и запустите установщик, затем нажмите «Запустить»."
+        : detail ? `Не удалось подключиться к помощнику: ${detail}` : "Помощник отключён. Нажмите «Запустить».", missing ? "missing" : "offline");
+    }
+  });
+  return port;
+}
+function nativeRequest(action, payload = {}) {
+  return new Promise((resolve, reject) => {
+    const id = crypto.randomUUID();
+    const timeout = setTimeout(() => {
+      pending.delete(id);
+      reject(new Error(action === "pick_folder" ? "Диалог выбора папки закрыт по тайм-ауту." : "Помощник отвечает слишком долго. Попробуйте снова."));
+    }, action === "ping" ? 4000 : action === "pick_folder" ? 600_000 : action === "inspect" ? 150_000 : 90_000);
+    pending.set(id, { resolve, reject, timeout });
+    let port;
+    try { port = connectHost(); port.postMessage({ id, action, payload }); }
+    catch (error) {
+      clearTimeout(timeout); pending.delete(id);
+      if (/disconnected port/i.test(error.message)) {
+        const failure = new Error("Связь с помощником прервана. Подключаюсь заново…");
+        failure.code = "NATIVE_PORT_DISCONNECTED";
+        if (nativePort === port) {
+          disconnect(failure.message, "offline");
+          try { port.disconnect(); } catch { /* Already disconnected. */ }
+        }
+        reject(failure);
+      } else reject(error);
+    }
+  });
+}
+function startHelper() {
+  if (!helperStartTask) helperStartTask = startHelperNow().finally(() => { helperStartTask = null; });
+  return helperStartTask;
+}
+async function startHelperNow() {
+  if (nativePort && helper.status !== "running" && !Object.values(jobs).some(job => job.status === "running")) {
+    const stale = nativePort; nativePort = null;
+    try { stale.disconnect(); } catch { /* Already disconnected. */ }
+  }
+  try {
+    for (let attempt = 0; attempt < 2; attempt++) {
+      try {
+        const hardware = await nativeRequest("hello");
+        const ping = await nativeRequest("ping");
+        if (!ping.alive) throw new Error("Помощник не подтвердил связь.");
+        const compatibility = checkHelperCompatibility(hardware, chrome.runtime.getManifest().version);
+        if (!compatibility.compatible) {
+          helperState("incompatible", compatibility.message, hardware, compatibility);
+          throw new Error(compatibility.message);
+        }
+        helperState("running", "Помощник отвечает. Загрузка и обработка доступны.", hardware, compatibility);
+        return hardware;
+      } catch (error) {
+        if (attempt === 0 && error.code === "NATIVE_PORT_DISCONNECTED") continue;
+        throw error;
+      }
+    }
+  } catch (error) {
+    if (helper.status === "checking" || helper.status === "running") helperState("error", error.message);
+    throw error;
+  }
+}
+async function checkHelper() {
+  if (helperStartTask) {
+    try { await helperStartTask; } catch { /* The connection publishes its status. */ }
+    return helper;
+  }
+  if (nativePort && helper.status === "running") {
+    try {
+      const ping = await nativeRequest("ping");
+      if (!ping.alive) throw new Error("Помощник не подтвердил связь.");
+      helperState("running", "Помощник отвечает. Загрузка и обработка доступны.", helper.hardware, helper.compatibility);
+    } catch (error) { if (helper.status === "running") helperState("error", error.message); }
+  }
+  if (!nativePort || helper.status !== "running") {
+    try { await startHelper(); } catch { /* Missing/offline status is returned below. */ }
+  }
+  return helper;
+}
+async function notify(job) {
+  const previous = notificationTimes.get(job.id) || 0;
+  if (job.status === "running" && Date.now() - previous < 1500) return;
+  notificationTimes.set(job.id, Date.now());
+  const id = `ytdl-${job.id}`;
+  try {
+    if (job.status === "running") {
+      const options = { type: "progress", iconUrl: "icons/128.png", title: job.title || "YouTubeDL",
+        message: [progressText(job), downloadSizeText(job) || processingText(job)].filter(Boolean).join("\n"), progress: Number.isFinite(job.percent) ? Math.round(job.percent) : 0,
+        silent: true };
+      if (!await chrome.notifications.update(id, options)) await chrome.notifications.create(id, options);
+    } else {
+      await chrome.notifications.clear(id);
+      if (job.status !== "cancelled") await chrome.notifications.create(id, {
+        type: "basic", iconUrl: "icons/128.png", title: job.status === "complete" ? job.kind === "update" ? "Обновление компонентов" : job.kind === "dependency" ? "Установка завершена" : "Файл сохранён" : "Ошибка",
+        message: job.result?.filename || job.result?.title || job.error || "Готово", silent: job.status !== "error",
+        ...(job.status === "complete" && job.result?.path ? { buttons: [{ title: "Показать файл" }] } : {}),
+      });
+    }
+  } catch { /* The on-page toast remains available if OS notifications are disabled. */ }
+}
+async function onJob(update) {
+  await ready;
+  if (update.error) update = { ...update, error: errorText(update.error) };
+  const context = jobContexts.get(update.id) || {};
+  const job = stabilizeDownloadSpeed({ ...jobs[update.id], ...update, speed: update.speed,
+    title: update.result?.title || context.title || update.title || jobs[update.id]?.title,
+    tabId: context.tabId ?? jobs[update.id]?.tabId }, jobs[update.id]);
+  jobs[job.id] = job;
+  broadcast({ event: "job", job });
+  if (Number.isInteger(job.tabId)) chrome.tabs.sendMessage(job.tabId, { type: "JOB_PROGRESS", job }).catch(() => {});
+  if (job.status !== "running" || !job.savedAt || Date.now() - job.savedAt > 1000) {
+    job.savedAt = Date.now(); saveJobs();
+  }
+  notify(job);
+  if (job.kind === "dependency" && job.status !== "running" && nativePort) startHelper().catch(() => {});
+  if (job.kind === "update" && job.status === "complete" && job.result?.restartRequired && nativePort) {
+    const previous = nativePort;
+    disconnect("Перезапускаю помощник с обновлёнными компонентами…", "checking");
+    previous.disconnect();
+    startHelper().catch(() => {});
+  }
+  chrome.action.setBadgeText({ text: Object.values(jobs).some(item => item.status === "running") ? "↓" : "" });
+  chrome.action.setBadgeBackgroundColor({ color: "#20a9de" });
+}
+
+async function handleUi(action, payload) {
+  await ready;
+  if (action === "session_status") return readSession(Number.isInteger(payload.tabId) ? payload.tabId : null);
+  if (action === "session_enable") {
+    if (payload.enabled && !await chrome.permissions.contains(SESSION_PERMISSION)) throw new Error("Разрешите использовать вход в YouTube в окне браузера.");
+    await chrome.storage.local.set({ youtubeSession: payload.enabled === true });
+    inspectionCache.clear();
+    if (!payload.enabled) await chrome.permissions.remove(SESSION_PERMISSION);
+    return readSession(Number.isInteger(payload.tabId) ? payload.tabId : null);
+  }
+  if (action === "state") return { jobs: Object.values(jobs), helper };
+  if (action === "open_history") {
+    const theme = ["light", "dark"].includes(payload.theme) ? payload.theme : "auto";
+    await chrome.tabs.create({ url: chrome.runtime.getURL(`history.html?theme=${theme}`) });
+    return { opened: true };
+  }
+  if (action === "helper_status") return checkHelper();
+  if (action === "hello" || action === "helper_start") return startHelper();
+  if (action === "update_settings") {
+    const settings = await nativeRequest(action, { enabled: payload.enabled });
+    if (helper.hardware) helper.hardware.updateSettings = settings;
+    helperState(helper.status, helper.message, helper.hardware, helper.compatibility);
+    return settings;
+  }
+  if (action === "helper_remove") {
+    if (!nativePort || helper.status !== "running") throw new Error("Сначала подключите помощник.");
+    if (Object.values(jobs).some(job => job.status === "running")) throw new Error("Дождитесь завершения загрузок перед удалением помощника.");
+    const result = await nativeRequest("helper_uninstall");
+    const old = nativePort;
+    disconnect("Помощник удалён. Для установки скачайте и запустите установщик.", "missing");
+    old?.disconnect();
+    return result;
+  }
+  if (!["hello", "inspect", "pick_folder", "download", "dependency_install", "helper_update", "cancel", "reveal", "jobs"].includes(action)) throw new Error("Неизвестная операция");
+  if (["inspect", "download"].includes(action) && !canonicalUrl(payload.url)) throw new Error("Нужна ссылка на видео YouTube");
+  if (["inspect", "download", "dependency_install", "helper_update"].includes(action) && (!nativePort || helper.status !== "running")) await startHelper();
+  if (["inspect", "download"].includes(action)) payload = await mediaPayload(payload);
+  if (action === "inspect") return inspectVideo(payload);
+  if (action === "download" && payload.workFolder) {
+    if (!nativePort || helper.status !== "running") await startHelper();
+    if (helper.hardware?.supportsWorkFolder !== true) throw new Error("Для отдельной рабочей папки установите помощник 1.3.1 или новее.");
+  }
+  if (["download", "dependency_install", "helper_update"].includes(action)) {
+    const title = String(payload.title || (action === "helper_update" ? "Обновление компонентов" : "Видео")).slice(0, 300);
+    const tabId = Number.isInteger(payload.tabId) ? payload.tabId : null;
+    const result = await nativeRequest(action, payload);
+    jobContexts.set(result.jobId, { title, tabId });
+    // Worker events may arrive immediately after the response, before this microtask.
+    onJob({ ...jobs[result.jobId], id: result.jobId, title, tabId, url: payload.url,
+      status: jobs[result.jobId]?.status || "running", stage: jobs[result.jobId]?.stage || "preparing",
+      kind: action === "helper_update" ? "update" : action === "dependency_install" ? "dependency" : "download",
+      ...(action === "helper_update" ? { canCancel: false } : {}),
+      createdAt: jobs[result.jobId]?.createdAt || Date.now() / 1000 });
+    return result;
+  }
+  return nativeRequest(action, payload);
+}
+
+async function mediaPayload(payload) {
+  // Ignore cookies supplied by callers; only the browser API is a session source.
+  const { browserCookies: ignoredCookies, ...options } = payload;
+  const session = await readSession(Number.isInteger(payload.tabId) ? payload.tabId : null, true);
+  if (session.status === "connected" && !helper.hardware?.supportsBrowserCookies) {
+    throw new Error("Обновите помощник для подключения входа: нажмите «Установить», запустите скачанный установщик и обновите расширение.");
+  }
+  return { ...options, ...(session.status === "connected" ? { browserCookies: session.cookies } : {}) };
+}
+
+async function inspectVideo(payload) {
+  // Only the summary is cached; URLs for downloading are refreshed by the worker.
+  const fingerprint = await crypto.subtle.digest("SHA-256", new TextEncoder().encode(JSON.stringify(payload.browserCookies || [])));
+  const key = `${canonicalUrl(payload.url)}|${payload.tabId || ""}|${[...new Uint8Array(fingerprint)].map(byte => byte.toString(16).padStart(2, "0")).join("")}`;
+  const cached = inspectionCache.get(key);
+  if (cached && cached.expires > Date.now() && !payload.refresh) return cached.task;
+  const entry = { expires: Date.now() + 45000, task: nativeRequest("inspect", payload) };
+  inspectionCache.delete(key); inspectionCache.set(key, entry);
+  if (inspectionCache.size > 20) inspectionCache.delete(inspectionCache.keys().next().value);
+  try { return await entry.task; }
+  catch (error) { if (inspectionCache.get(key) === entry) inspectionCache.delete(key); throw error; }
+}
+
+async function quickDownload(url, tabId) {
+  url = canonicalUrl(url);
+  if (!url) throw new Error("Нужна ссылка на видео YouTube.");
+  const { preferences = {} } = await chrome.storage.local.get("preferences");
+  if (!preferences.folder) return { needSetup: true, error: "Сначала выберите папку и сохраните настройки скачивания." };
+  if (Object.values(jobs).filter(job => job.status === "running").length >= 2) {
+    return { needSetup: true, error: "Уже выполняются две операции. Дождитесь завершения одной." };
+  }
+  const temporaryId = `preparing-${crypto.randomUUID()}`;
+  jobContexts.set(temporaryId, { tabId, title: "Подготовка скачивания" });
+  await onJob({ id: temporaryId, url, status: "running", stage: "preparing", percent: null, canCancel: false, transient: true, createdAt: Date.now() / 1000 });
+  try {
+    await startHelper();
+    if (helper.hardware?.ready === false) throw new Error("Установите недостающие компоненты через настройки скачивания.");
+    const metadata = await handleUi("inspect", { url, tabId });
+    const result = await handleUi("download", { ...preferenceOptions(metadata, preferences), url, title: metadata.title, tabId });
+    delete jobs[temporaryId]; jobContexts.delete(temporaryId);
+    broadcast({ event: "remove_job", jobId: temporaryId });
+    chrome.tabs.sendMessage(tabId, { type: "REMOVE_JOB", jobId: temporaryId }).catch(() => {});
+    chrome.notifications.clear(`ytdl-${temporaryId}`).catch(() => {});
+    saveJobs();
+    return { ok: true, jobId: result.jobId };
+  } catch (error) {
+    await onJob({ id: temporaryId, status: "error", stage: "error", error: error.message, transient: false });
+    return { ok: false, needSetup: helper.status !== "running" || /папк|компонент|вход|авторизац|бот|помощник|проверку/i.test(error.message), error: error.message };
+  }
+}
+
+chrome.runtime.onConnect.addListener(port => {
+  const pageUrl = port.sender?.url?.split(/[?#]/)[0];
+  if (port.name !== "ytdl-ui" || port.sender?.id !== chrome.runtime.id ||
+      !["downloader.html", "history.html"].some(page => pageUrl === chrome.runtime.getURL(page))) return;
+  clients.add(port);
+  ready.then(() => port.postMessage({ event: "state", jobs: Object.values(jobs), helper })).catch(() => {});
+  port.onDisconnect.addListener(() => clients.delete(port));
+  port.onMessage.addListener(async message => {
+    try { port.postMessage({ id: message.id, ok: true, result: await handleUi(message.action, message.payload || {}) }); }
+    catch (error) {
+      // Save failures before a worker was created; worker failures arrive through onJob.
+      const titles = { inspect: "Получение качества видео", download: "Подготовка скачивания", dependency_install: "Установка компонента", helper_update: "Обновление компонентов" };
+      if (titles[message.action]) {
+        const payload = message.payload || {};
+        await onJob({ id: `error-${crypto.randomUUID()}`, title: String(payload.title || titles[message.action]).slice(0, 300),
+          url: canonicalUrl(payload.url), status: "error", stage: "error", error: error.message,
+          kind: message.action === "inspect" ? "inspection" : message.action === "helper_update" ? "update" : message.action === "dependency_install" ? "dependency" : "download",
+          createdAt: Date.now() / 1000 }).catch(() => {});
+      }
+      try { port.postMessage({ id: message.id, ok: false, error: error.message }); } catch {}
+    }
+  });
+});
+
+async function openWindow(url, tabId, theme = "auto") {
+  const query = new URLSearchParams({ url: canonicalUrl(url) || "", tabId: String(tabId || ""), theme });
+  await chrome.windows.create({ url: chrome.runtime.getURL(`downloader.html?${query}`), type: "popup", width: 520, height: 820 });
+}
+chrome.action.onClicked.addListener(tab => openWindow(tab.url, tab.id));
+chrome.runtime.onMessage.addListener((message, sender, respond) => {
+  if (message.type === "CLOSE_MENU" && sender.id === chrome.runtime.id && sender.tab &&
+      sender.url?.startsWith(chrome.runtime.getURL("downloader.html"))) {
+    chrome.tabs.sendMessage(sender.tab.id, { type: "CLOSE_MENU" })
+      .then(() => respond({ ok: true }), () => respond({ ok: true }));
+    return true;
+  }
+  let isYouTube = false;
+  try { const origin = new URL(sender.url); isYouTube = origin.protocol === "https:" && ["www.youtube.com", "m.youtube.com"].includes(origin.hostname); } catch {}
+  if (sender.id !== chrome.runtime.id || !sender.tab || !isYouTube) return false;
+  const tabId = sender.tab.id;
+  if (message.type === "QUICK_DOWNLOAD") {
+    quickDownload(message.url, tabId).then(respond, error => respond({ needSetup: true, error: error.message }));
+    return true;
+  }
+  if (message.type === "GET_CONTEXT") { respond({ tabId, jobs: Object.values(jobs).filter(job => job.tabId === tabId) }); return false; }
+  if (message.type === "OPEN_WINDOW") {
+    openWindow(sender.url, tabId).then(() => respond({ ok: true }), error => respond({ ok: false, error: error.message })); return true;
+  }
+  if (["CANCEL_JOB", "REVEAL_JOB"].includes(message.type) && jobs[message.jobId]?.tabId === tabId) {
+    nativeRequest(message.type === "CANCEL_JOB" ? "cancel" : "reveal", { jobId: message.jobId })
+      .then(result => respond({ ok: true, result }), error => respond({ ok: false, error: error.message }));
+    return true;
+  }
+  return false;
+});
+chrome.notifications.onButtonClicked.addListener((id, index) => {
+  if (index === 0 && id.startsWith("ytdl-")) nativeRequest("reveal", { jobId: id.slice(5) }).catch(() => {});
+});

extension/content.js

@@ -0,0 +1,100 @@
+(() => {
+  let toastHost, toastRoot, tabId = null;
+  const dismissed = new Set();
+  const toastTimers = new Map();
+  const knownJobs = new Map();
+  const stages = { preparing: "Подготовка", downloading: "Скачивание", merging: "Объединение дорожек", remuxing: "Подготовка файла", finalizing: "Финализация файла", encoding: "Перекодирование", audio: "Обработка аудио", saving: "Сохранение файла", installing: "Установка", updating: "Обновление компонентов", complete: "Файл сохранён", error: "Ошибка", cancelled: "Отменено", cancelling: "Останавливаю обработку" };
+  const isDark = () => document.documentElement.hasAttribute("dark") || document.documentElement.dataset.theme === "dark";
+  function updateText(node, value) {
+    if (node.textContent === value) return;
+    if (node.childNodes.length === 1 && node.firstChild.nodeType === 3) node.firstChild.data = value;
+    else node.textContent = value;
+  }
+  function downloadSizeText(job) {
+    const megabytes = value => `${(value / 1048576).toLocaleString("ru-RU", { minimumFractionDigits: 1, maximumFractionDigits: 1 })} МБ`;
+    if (job.status === "complete" && Number.isFinite(job.result?.size) && job.result.size >= 0) return `Размер файла: ${megabytes(job.result.size)}`;
+    const value = job.stage === "saving" ? job.copied : job.downloaded;
+    if (!["downloading", "saving"].includes(job.stage) || !Number.isFinite(value) || value < 0) return "";
+    const downloaded = `${job.stage === "saving" ? "Сохранено" : "Скачано"} ${megabytes(value)}`;
+    return Number.isFinite(job.total) && job.total > 0 ? `${downloaded} из ${megabytes(job.total)}` : downloaded;
+  }
+  function processingText(job) {
+    if (!["merging", "remuxing", "finalizing", "encoding", "audio"].includes(job.stage)) return "";
+    const duration = value => {
+      const seconds = Math.floor(value);
+      return seconds >= 3600 ? `${Math.floor(seconds / 3600)}:${String(Math.floor(seconds / 60) % 60).padStart(2, "0")}:${String(seconds % 60).padStart(2, "0")}` : `${Math.floor(seconds / 60)}:${String(seconds % 60).padStart(2, "0")}`;
+    };
+    const parts = [];
+    if (Number.isFinite(job.processedSeconds) && job.processedSeconds >= 0) parts.push(`Обработано ${duration(job.processedSeconds)}${job.durationSeconds > 0 ? ` из ${duration(job.durationSeconds)}` : ""}`);
+    if (Number.isFinite(job.written) && job.written >= 0) parts.push(`Записано ${(job.written / 1048576).toLocaleString("ru-RU", { minimumFractionDigits: 1, maximumFractionDigits: 1 })} МБ`);
+    return parts.join(" · ");
+  }
+  const commonStyle = ` :host{font-family:Roboto,"Segoe UI",sans-serif;color-scheme:light;--bg:#fff;--fg:#152334;--muted:#6a7787;--line:#e1e7ee;--track:#edf2f7;--accent:#0788bc}:host([dark]){color-scheme:dark;--bg:#1b2029;--fg:#eef2fa;--muted:#a1adbd;--line:#333e4e;--track:#2b3543;--accent:#59d0f4}*{box-sizing:border-box}button{font:inherit;cursor:pointer}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important}}`;
+  function applyTheme() { toastHost?.toggleAttribute("dark", isDark()); }
+  function ensureToasts() {
+    if (toastHost?.isConnected) return;
+    toastHost = document.createElement("div"); toastHost.id = "ytdl-notifications";
+    toastHost.style.cssText = "position:fixed;right:20px;bottom:20px;width:min(365px,calc(100vw - 32px));z-index:2147483647;pointer-events:none";
+    toastRoot = toastHost.attachShadow({ mode: "open" });
+    toastRoot.innerHTML = `<style>${commonStyle}.transfer{font-size:11px;color:var(--muted);margin-top:8px;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}.toast{background:var(--bg);color:var(--fg);border:1px solid var(--line);border-radius:16px;padding:15px;margin-top:9px;box-shadow:0 12px 38px #0003;pointer-events:auto;animation:toast-in .32s cubic-bezier(.2,.8,.2,1) both;position:relative}.top{display:flex;gap:11px;align-items:center}.icon{width:35px;height:35px;display:grid;place-items:center;flex-shrink:0;border-radius:11px;background:color-mix(in srgb,var(--accent) 13%,var(--bg));color:var(--accent);font-size:24px}.copy{min-width:0;flex:1}.title{font-size:12px;font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.stage{font-size:11px;color:var(--muted);margin-top:4px}.dismiss{border:0;background:transparent;color:var(--muted);font-size:20px;align-self:flex-start;line-height:16px;padding:0 0 0 3px}.track{height:5px;background:var(--track);border-radius:5px;margin-top:13px;overflow:hidden}.fill{height:100%;border-radius:5px;background:linear-gradient(90deg,#149bce,#59ded5);transition:width .3s ease;position:relative;overflow:hidden}.toast[data-status=running] .fill:not(.indeterminate):after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,transparent,#fff6,transparent);animation:shine 1.6s linear infinite}.fill.indeterminate{width:35%!important;transition:none;animation:slide 1.7s infinite ease-in-out}.bottom{display:flex;justify-content:space-between;align-items:center;margin-top:9px;font-size:10px;color:var(--muted)}.action{border:0;background:none;color:var(--accent);font-size:11px;padding:0}.complete .icon{background:#35c99820;color:#22b98a}.error .icon{background:#ff656520;color:#e67171}.toast.exit{animation:toast-out .18s ease-in forwards}.encoding .icon{animation:pulse 1.8s infinite}.label{font-variant-numeric:tabular-nums;overflow:hidden;white-space:nowrap;text-overflow:ellipsis;max-width:235px}@keyframes toast-in{from{opacity:0;transform:translateY(18px) scale(.96)}to{opacity:1;transform:translateY(0) scale(1)}}@keyframes toast-out{to{opacity:0;transform:translateX(30px)}}@keyframes shine{from{transform:translateX(-100%)}to{transform:translateX(100%)}}@keyframes slide{0%,100%{transform:translateX(0)}50%{transform:translateX(calc(100% / .35 - 100%))}}@keyframes pulse{50%{box-shadow:0 0 0 5px #31bee912}}@media(max-width:450px){.toast{padding:12px}} </style>`;
+    document.documentElement.append(toastHost); applyTheme();
+  }
+  function dismiss(id) {
+    dismissed.add(id); clearTimeout(toastTimers.get(id));
+    const toast = toastRoot?.querySelector(`[data-id="${CSS.escape(id)}"]`);
+    toast?.classList.add("exit"); setTimeout(() => toast?.remove(), 180);
+  }
+  function showJob(job) {
+    knownJobs.set(job.id, job);
+    if (dismissed.has(job.id)) return;
+    ensureToasts();
+    let toast = toastRoot.querySelector(`[data-id="${CSS.escape(job.id)}"]`);
+    if (!toast) {
+      toast = document.createElement("article"); toast.className = "toast"; toast.dataset.id = job.id;
+      toast.setAttribute("role", "status"); toast.setAttribute("aria-live", "polite");
+      toast.innerHTML = '<div class="top"><div class="icon">↓</div><div class="copy"><div class="title"></div><div class="stage"></div></div><button class="dismiss" aria-label="Скрыть уведомление">×</button></div><div class="track"><div class="fill"></div></div><div class="transfer" hidden></div><div class="bottom"><span class="label"></span><button class="action"></button></div>';
+      toast.querySelector(".dismiss").addEventListener("click", () => dismiss(job.id));
+      toast.querySelector(".action").addEventListener("click", () => {
+        const current = knownJobs.get(job.id);
+        chrome.runtime.sendMessage({ type: current.status === "complete" ? "REVEAL_JOB" : "CANCEL_JOB", jobId: job.id }).catch(() => {});
+      });
+      toastRoot.append(toast);
+    }
+    const className = `toast ${job.stage}`;
+    if (toast.className !== className) toast.className = className;
+    if (toast.dataset.status !== job.status) toast.dataset.status = job.status;
+    updateText(toast.querySelector(".title"), job.title || "YouTubeDL");
+    const suffix = job.stage === "downloading" ? ` · ${job.track === "audio" ? "аудио" : "видео"}` : ["encoding", "audio"].includes(job.stage) && job.engine ? ` · ${{ nvenc: "NVIDIA NVENC", amf: "AMD AMF", cpu: "CPU", copy: "без перекодирования" }[job.engine] || job.engine}` : ["merging", "remuxing"].includes(job.stage) && !job.message ? " · без перекодирования" : "";
+    updateText(toast.querySelector(".stage"), (job.stage === "complete" && job.kind === "update" ? job.result?.title || "Обновление завершено" : ["updating", "merging", "remuxing", "finalizing", "encoding", "audio"].includes(job.stage) && job.message ? job.message : job.stage === "complete" && job.kind === "dependency" ? "Установка завершена" : stages[job.stage] || "Обработка") + suffix);
+    updateText(toast.querySelector(".icon"), { complete: "✓", error: "!", cancelled: "×", encoding: "✦", merging: "⇄", remuxing: "⇄", audio: "♫" }[job.stage] || "↓");
+    const fill = toast.querySelector(".fill");
+    const width = `${Number.isFinite(job.percent) ? Math.max(0, Math.min(100, job.percent)) : 0}%`;
+    if (fill.style.width !== width) fill.style.width = width;
+    fill.classList.toggle("indeterminate", job.status === "running" && !Number.isFinite(job.percent));
+    toast.querySelector(".track").hidden = ["error", "cancelled"].includes(job.status);
+    const transfer = toast.querySelector(".transfer");
+    updateText(transfer, downloadSizeText(job) || processingText(job)); transfer.hidden = !transfer.textContent;
+    let label = Number.isFinite(job.percent) ? `${Math.round(job.percent)}%` : "";
+    if (job.stage === "downloading" && Number.isFinite(job.speed) && job.speed >= 0) label += `${label ? " · " : ""}${(job.speed / 1048576).toFixed(1)} МБ/с`;
+    if (["merging", "remuxing", "encoding", "audio"].includes(job.stage) && job.speed) label += `${label ? " · " : ""}${job.speed}`;
+    if (["merging", "remuxing", "encoding", "audio"].includes(job.stage) && Number.isFinite(job.eta) && job.eta > 0) label += `${label ? " · " : ""}осталось ≈ ${Math.ceil(job.eta)} с`;
+    if (job.status === "complete") label = job.result?.filename || job.result?.title || "Готово";
+    if (job.status === "error") label = job.error || "Ошибка";
+    const readout = toast.querySelector(".label");
+    updateText(readout, label);
+    const tooltip = job.error || job.result?.path || label;
+    if (readout.title !== tooltip) readout.title = tooltip;
+    const action = toast.querySelector(".action");
+    updateText(action, job.status === "complete" ? "Открыть папку ↗" : "Отменить");
+    action.hidden = !["running", "complete"].includes(job.status) || job.canCancel === false || (["dependency", "update"].includes(job.kind) && job.status === "complete");
+    if (job.status !== "running" && !toastTimers.has(job.id)) toastTimers.set(job.id, setTimeout(() => dismiss(job.id), job.status === "error" ? 60000 : 20000));
+  }
+  chrome.runtime.onMessage.addListener(message => {
+    if (message.type === "JOB_PROGRESS") showJob(message.job);
+    if (message.type === "REMOVE_JOB") dismiss(message.jobId);
+  });
+  new MutationObserver(applyTheme).observe(document.documentElement, { attributes: true, attributeFilter: ["dark", "data-theme"] });
+  chrome.runtime.sendMessage({ type: "GET_CONTEXT" }).then(context => {
+    tabId = context?.tabId; for (const job of context?.jobs || []) if (job.status === "running") showJob(job);
+  }).catch(() => {});
+})();

extension/controls.js

@@ -0,0 +1,261 @@
+(() => {
+  const controls = new Set();
+  const previews = new WeakMap();
+  const previewLayouts = new Set();
+  let layoutScheduled = false;
+  const previewResize = new ResizeObserver(schedulePreviewLayout);
+  let watchButton = null, shortsButton = null, shortsRenderer = null;
+  let menu = null, menuAnchor = null, menuSize = { width: 270, height: 142 };
+  const icon = '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M12 3v12m-5-5 5 5 5-5M4 17v4h16v-4"/></svg>';
+  const gear = '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="m9 3-.6 2.4-2.1 1.2L4 6l-2 3.5 1.8 1.7v2.4L2 15.3 4 19l2.3-.6 2.1 1.2L9 22h4l.6-2.4 2.1-1.2 2.3.6 2-3.7-1.8-1.7v-2.4L20 9.5 18 6l-2.3.6-2.1-1.2L13 3Z" transform="translate(1 -.5) scale(.95)"/><circle cx="12" cy="12" r="3"/></svg>';
+  const themeStyle = ':host{font-family:Roboto,"Segoe UI",sans-serif;--bg:#fff;--fg:#0f0f0f;--muted:#606060;--button:#0000000d;--hover:#0000001a;--pressed:#00000026;--line:#0000001a}:host([dark]){--bg:#212121;--fg:#f1f1f1;--muted:#aaa;--button:#ffffff1a;--hover:#ffffff33;--pressed:#ffffff40;--line:#ffffff1a}*{box-sizing:border-box}button{font:inherit;cursor:pointer}';
+  const dark = () => document.documentElement.hasAttribute('dark') || document.documentElement.dataset.theme === 'dark';
+  function canonical(value) {
+    try {
+      const parsed = new URL(value, location.href);
+      if (parsed.protocol !== 'https:' || !['www.youtube.com', 'm.youtube.com', 'youtube.com', 'youtu.be'].includes(parsed.hostname)) return null;
+      const match = parsed.pathname.match(/^\/(?:shorts|live)\/([\w-]{11})(?:\/|$)/);
+      const id = parsed.hostname === 'youtu.be' ? parsed.pathname.slice(1) : parsed.pathname === '/watch' ? parsed.searchParams.get('v') : match?.[1];
+      return /^[\w-]{11}$/.test(id || '') ? `https://www.youtube.com/watch?v=${id}` : null;
+    } catch { return null; }
+  }
+  function theme() {
+    for (const control of controls) {
+      if (!control.isConnected) { controls.delete(control); continue; }
+      control.toggleAttribute('dark', control.dataset.kind === 'thumbnail' || dark());
+    }
+    menu?.toggleAttribute('dark', dark());
+    menu?.querySelector('iframe')?.contentWindow?.postMessage({ type: 'YTDL_THEME', theme: dark() ? 'dark' : 'light' }, chrome.runtime.getURL('').slice(0, -1));
+  }
+  function closeMenu() {
+    if (!menu) return;
+    const closing = menu; menu = null; menuAnchor = null;
+    closing.id = ''; closing.style.animation = 'none'; closing.classList.add('ytdl-closing');
+    setTimeout(() => closing.remove(), 150);
+  }
+  function positionMenu() {
+    if (!menu || !menuAnchor) return;
+    if (!menuAnchor.isConnected) { closeMenu(); return; }
+    const rect = menuAnchor.getBoundingClientRect();
+    const width = Math.min(menuSize.width, innerWidth - 24);
+    const height = Math.min(menuSize.height, innerHeight - 32);
+    const left = Math.min(Math.max(12, rect.left), innerWidth - width - 12);
+    const top = rect.bottom + height + 16 < innerHeight ? rect.bottom + 8
+      : Math.max(12, Math.min(rect.top - height - 8, innerHeight - height - 16));
+    Object.assign(menu.style, { width: `${width}px`, height: `${height}px`, left: `${left}px`, top: `${top}px` });
+  }
+  function newMenu(trigger, size) {
+    closeMenu(); menuAnchor = trigger; menuSize = size;
+    menu = document.createElement('div'); menu.id = 'ytdl-menu';
+    menu.style.cssText = 'position:fixed;z-index:2147483646;border-radius:14px;overflow:hidden;box-shadow:0 12px 40px #0005,0 0 0 1px #80808033;animation:ytdl-menu-in .16s ease-out both';
+    document.documentElement.append(menu); theme(); positionMenu();
+    return menu;
+  }
+  async function openSetup(trigger, url, notice = '') {
+    let context;
+    try { context = await chrome.runtime.sendMessage({ type: 'GET_CONTEXT' }); } catch { return; }
+    if (!trigger.isConnected) return;
+    const panel = newMenu(trigger, { width: 460, height: 780 });
+    const frame = document.createElement('iframe');
+    const params = new URLSearchParams({ url, tabId: String(context?.tabId || ''), embedded: '1', theme: dark() ? 'dark' : 'light', notice });
+    frame.src = chrome.runtime.getURL(`downloader.html?${params}`);
+    frame.title = 'Настроить скачивание'; frame.style.cssText = 'border:0;width:100%;height:100%;display:block';
+    panel.append(frame);
+  }
+  async function download(trigger, url) {
+    if (!url) return;
+    closeMenu();
+    try {
+      const response = await chrome.runtime.sendMessage({ type: 'QUICK_DOWNLOAD', url });
+      if (response?.needSetup) openSetup(trigger, url, response.error || 'Выберите папку и сохраните настройки.');
+    } catch (error) { openSetup(trigger, url, error.message); }
+  }
+  function makeControl(kind, resolveUrl) {
+    const host = document.createElement('span'); host.dataset.ytdlControl = 'true'; host.dataset.kind = kind;
+    const shadow = host.attachShadow({ mode: 'open' });
+    shadow.innerHTML = `<style>${themeStyle}.pair{display:flex;align-items:center;gap:6px}button{display:flex;align-items:center;justify-content:center;gap:6px;height:36px;padding:0 16px;border:0;border-radius:999px;background:var(--button);color:var(--fg);font-size:14px;font-weight:500;white-space:nowrap}button:hover{background:var(--hover)}button:active{background:var(--pressed)}button:focus-visible{outline:2px solid var(--fg);outline-offset:2px}.glyph{display:grid;place-items:center}svg{width:20px;height:20px}.settings{width:36px;padding:0}:host([data-kind=thumbnail]) button{width:34px;height:34px;padding:0;background:#0f0f0fbb;color:#fff;box-shadow:0 1px 5px #0003}:host([data-kind=thumbnail]) button:hover{background:#303030}:host([data-kind=thumbnail]) .label{display:none}:host([data-kind=shorts]) .pair{flex-direction:column;gap:9px}:host([data-kind=shorts]) .download{background:transparent;height:auto;padding:0;flex-direction:column;gap:6px;color:var(--fg)}:host([data-kind=shorts]) .glyph{width:48px;height:48px;border-radius:50%;background:var(--button)}:host([data-kind=shorts]) .download:hover .glyph{background:var(--hover)}:host([data-kind=shorts]) .download:active .glyph{background:var(--pressed)}:host([data-kind=shorts]) svg{width:24px;height:24px}:host([data-kind=shorts]) .settings svg{width:19px;height:19px}:host([data-kind=shorts]) .label{font-size:12px}</style><div class="pair"><button class="download" type="button" title="Скачать по сохранённым настройкам" aria-label="Скачать по сохранённым настройкам"><span class="glyph">${icon}</span><span class="label">Скачать</span></button><button class="settings" type="button" title="Настройки скачивания" aria-label="Настройки скачивания">${gear}</button></div>`;
+    for (const button of shadow.querySelectorAll('button')) {
+      button.addEventListener('pointerdown', event => { event.stopPropagation(); });
+      button.addEventListener('keydown', event => { event.stopPropagation(); });
+      button.addEventListener('click', event => {
+        event.preventDefault(); event.stopPropagation();
+        const url = resolveUrl(); if (!url) return;
+        if (button.classList.contains('download')) download(host, url);
+        else if (menuAnchor === host) closeMenu(); else openSetup(host, url);
+      });
+    }
+    controls.add(host); return host;
+  }
+  function attachWatch() {
+    if (!canonical(location.href) || location.pathname.startsWith('/shorts/')) { watchButton?.remove(); watchButton = null; return; }
+    if (watchButton?.isConnected) return;
+    const subscribe = document.querySelector('ytd-watch-metadata #subscribe-button, ytd-video-owner-renderer #subscribe-button, ytm-slim-video-metadata-renderer ytm-subscribe-button-renderer');
+    if (!subscribe) return;
+    watchButton = makeControl('watch', () => canonical(location.href)); watchButton.id = 'ytdl-subscribe-download';
+    watchButton.style.cssText = 'display:inline-flex;align-items:center;flex-shrink:0;margin-inline-start:8px;vertical-align:middle';
+    subscribe.after(watchButton);
+  }
+  function styleValue(node, key, value) { if (node.style[key] !== value) node.style[key] = value; }
+  function usableRect(element) {
+    if (!element?.isConnected || getComputedStyle(element).visibility === 'hidden') return null;
+    const rect = element.getBoundingClientRect();
+    return rect.width >= 90 && rect.height >= 50 ? rect : null;
+  }
+  function picture(link, root) {
+    // A title link is a video URL too, but must never become a positioning anchor.
+    const media = [...link.querySelectorAll('img, video')].find(element => usableRect(element));
+    const frame = link.closest('ytd-thumbnail, yt-thumbnail-view-model') || link.querySelector('yt-thumbnail-view-model, yt-image');
+    const element = media || (usableRect(frame) ? frame : null);
+    if (!element) return null;
+    let rect = usableRect(element);
+    const crop = usableRect(frame);
+    if (crop && rect) {
+      const left = Math.max(rect.left, crop.left), top = Math.max(rect.top, crop.top);
+      const right = Math.min(rect.right, crop.right), bottom = Math.min(rect.bottom, crop.bottom);
+      rect = { left, top, right, bottom, width: right - left, height: bottom - top };
+    }
+    return rect?.width >= 90 && rect.height >= 50 && root.contains(element) ? { element, rect } : null;
+  }
+  function observePicture(preview, element) {
+    if (preview.element === element) return;
+    if (preview.element && preview.element !== preview.root) previewResize.unobserve(preview.element);
+    preview.element = element; previewResize.observe(element);
+  }
+  function visibleOverlay(root, left, top) {
+    let clip = { left: 0, top: 0, right: innerWidth, bottom: innerHeight };
+    // YouTube's absolutely positioned ytd-app leaves BODY with height 0.
+    // BODY/HTML overflow applies to the viewport, already handled above.
+    for (let element = root; element && element !== document.body && element !== document.documentElement; element = element.parentElement) {
+      const css = getComputedStyle(element);
+      if (css.display === 'contents' || css.display === 'inline') continue;
+      const x = /hidden|clip|auto|scroll/.test(css.overflowX), y = /hidden|clip|auto|scroll/.test(css.overflowY);
+      if (!x && !y) continue;
+      const rect = element.getBoundingClientRect();
+      if (x) { clip.left = Math.max(clip.left, rect.left); clip.right = Math.min(clip.right, rect.right); }
+      if (y) { clip.top = Math.max(clip.top, rect.top); clip.bottom = Math.min(clip.bottom, rect.bottom); }
+    }
+    return left >= clip.left && left + 74 <= clip.right && top >= clip.top && top + 34 <= clip.bottom;
+  }
+  function positionPreview(preview) {
+    const { root, host, floating } = preview;
+    if (!root.isConnected) {
+      previewResize.unobserve(root);
+      if (preview.element) previewResize.unobserve(preview.element);
+      previewLayouts.delete(preview); previews.delete(root); controls.delete(host); host.remove(); return;
+    }
+    let measured = preview.link?.isConnected && picture(preview.link, root);
+    if (!measured && floating) {
+      const link = [...root.querySelectorAll('a[href]')].find(candidate => canonical(candidate.href) && picture(candidate, root));
+      if (link) { preview.link = link; measured = picture(link, root); }
+    }
+    const base = root.getBoundingClientRect();
+    if (measured) {
+      observePicture(preview, measured.element);
+      const scale = root.offsetWidth ? base.width / root.offsetWidth : 1;
+      preview.box = { left: (measured.rect.left - base.left) / scale, top: (measured.rect.top - base.top) / scale,
+        width: measured.rect.width / scale, height: measured.rect.height / scale, rootWidth: root.offsetWidth };
+    }
+    // A Shorts hover player may remove or hide the original picture. Its buttons
+    // live outside that subtree and retain the last measured image rectangle.
+    let rect = measured?.rect;
+    if (!rect && floating && preview.box && base.width > 0) {
+      const factor = base.width / preview.box.rootWidth;
+      rect = { left: base.left + preview.box.left * factor, top: base.top + preview.box.top * factor,
+        width: preview.box.width * factor, height: preview.box.height * factor };
+      rect.right = rect.left + rect.width; rect.bottom = rect.top + rect.height;
+    }
+    if (!rect || rect.width < 90 || rect.height < 50) { styleValue(host, 'display', 'none'); return; }
+    if (floating) {
+      const top = rect.bottom - 42, left = rect.left + 8;
+      const visible = visibleOverlay(root, left, top);
+      styleValue(host, 'display', visible ? 'inline-flex' : 'none');
+      styleValue(host, 'left', `${left}px`); styleValue(host, 'top', `${top}px`);
+    } else {
+      styleValue(host, 'display', 'inline-flex');
+      const parent = host.offsetParent;
+      if (!parent) return;
+      const origin = parent.getBoundingClientRect();
+      const sx = parent.offsetWidth ? origin.width / parent.offsetWidth : 1;
+      const sy = parent.offsetHeight ? origin.height / parent.offsetHeight : sx;
+      styleValue(host, 'left', `${(rect.left - origin.left) / sx - parent.clientLeft + parent.scrollLeft + 8}px`);
+      styleValue(host, 'top', `${(rect.bottom - origin.top) / sy - parent.clientTop + parent.scrollTop - 42}px`);
+    }
+  }
+  function schedulePreviewLayout() {
+    if (layoutScheduled) return;
+    layoutScheduled = true;
+    requestAnimationFrame(() => { layoutScheduled = false; for (const preview of previewLayouts) positionPreview(preview); positionMenu(); });
+  }
+  let previewSequence = 0;
+  function attachThumbnails() {
+    const links = document.querySelectorAll('a#thumbnail[href], ytd-thumbnail a[href], yt-thumbnail-view-model a[href], a.yt-lockup-view-model__content-image[href], a.ytLockupViewModelContentImage[href], yt-shorts-lockup-view-model a[href], ytm-shorts-lockup-view-model a[href], ytd-reel-item-renderer a[href]');
+    for (const link of links) {
+      const url = canonical(link.href);
+      if (!url) continue;
+      const card = link.closest('ytm-shorts-lockup-view-model, yt-shorts-lockup-view-model, ytd-reel-item-renderer');
+      const root = card || link.closest('ytd-thumbnail, yt-thumbnail-view-model') || link.querySelector('yt-thumbnail-view-model') || link;
+      const measured = picture(link, root);
+      // Ignore metadata links even when a multiline title has thumbnail-like dimensions.
+      if (!measured) continue;
+      let preview = previews.get(root);
+      if (!preview?.host.isConnected) {
+        const host = makeControl('thumbnail', () => {
+          const current = previews.get(root);
+          const live = current?.link?.isConnected ? canonical(current.link.href) : null;
+          return live || [...root.querySelectorAll('a[href]')].map(anchor => canonical(anchor.href)).find(Boolean) || current?.url;
+        });
+        host.className = 'ytdl-thumbnail-download';
+        const key = `ytdl-preview-${++previewSequence}`; root.dataset.ytdlPreview = key; host.dataset.ytdlPreviewFor = key;
+        host.style.cssText = `position:${card ? 'fixed' : 'absolute'};left:0;top:0;width:74px;height:34px;margin:0;padding:0;line-height:1;z-index:2147483644;display:inline-flex`;
+        if (card) document.documentElement.append(host);
+        else {
+          if (getComputedStyle(root).position === 'static') root.style.position = 'relative';
+          if (getComputedStyle(root).display === 'inline') root.style.display = 'block';
+          root.append(host);
+        }
+        preview = { root, host, floating: Boolean(card), url, link };
+        previews.set(root, preview); previewLayouts.add(preview); previewResize.observe(root);
+      }
+      preview.url = url; preview.link = link; observePicture(preview, measured.element); positionPreview(preview);
+    }
+    schedulePreviewLayout();
+  }
+  function attachShorts() {
+    if (!location.pathname.startsWith('/shorts/') || !canonical(location.href)) {
+      shortsButton?.remove(); shortsButton = null; shortsRenderer = null; return;
+    }
+    const renderer = document.querySelector('ytd-reel-video-renderer[is-active], ytd-reel-video-renderer[active], ytd-shorts ytd-reel-video-renderer, ytm-reel-video-renderer');
+    const rail = renderer?.querySelector('reel-action-bar-view-model, #actions, #actions-container, .action-container, .reel-player-overlay-actions');
+    if (shortsButton?.isConnected && renderer === shortsRenderer && (!rail || shortsButton.parentElement === rail)) return;
+    shortsButton?.remove(); shortsRenderer = renderer;
+    shortsButton = makeControl('shorts', () => canonical(location.href)); shortsButton.id = 'ytdl-shorts-download';
+    if (rail) {
+      shortsButton.style.cssText = 'display:flex;justify-content:center;margin-top:16px;flex-shrink:0';
+      rail.append(shortsButton);
+    } else {
+      shortsButton.style.cssText = 'position:fixed;right:16px;bottom:180px;z-index:2147483645;display:inline-flex';
+      document.documentElement.append(shortsButton);
+    }
+  }
+  function attach() { attachWatch(); attachThumbnails(); attachShorts(); theme(); }
+  chrome.runtime.onMessage.addListener(message => { if (message.type === 'CLOSE_MENU') closeMenu(); });
+  document.addEventListener('pointerdown', event => {
+    if (menu && !event.composedPath().includes(menu) && !event.composedPath().includes(menuAnchor)) closeMenu();
+  }, true);
+  document.addEventListener('keydown', event => { if (event.key === 'Escape') closeMenu(); });
+  window.addEventListener('resize', () => { positionMenu(); schedulePreviewLayout(); });
+  window.addEventListener('scroll', () => { positionMenu(); schedulePreviewLayout(); }, { passive: true, capture: true });
+  document.addEventListener('yt-navigate-finish', () => { closeMenu(); attach(); });
+  window.addEventListener('popstate', () => { closeMenu(); attach(); });
+  let scheduled = false;
+  new MutationObserver(records => {
+    const relevant = records.filter(record => !record.target.closest?.('[data-ytdl-control], #ytdl-menu, #ytdl-notifications'));
+    if (!relevant.length) return;
+    schedulePreviewLayout();
+    if (!relevant.some(record => record.type === 'childList' || ['dark', 'is-active', 'href'].includes(record.attributeName))) return;
+    if (!scheduled) { scheduled = true; setTimeout(() => { scheduled = false; attach(); }, 200); }
+  }).observe(document.documentElement, { childList: true, subtree: true, attributes: true, attributeFilter: ['dark', 'is-active', 'href', 'class', 'style', 'hidden'] });
+  const style = document.createElement('style');
+  style.textContent = '@keyframes ytdl-menu-in{from{opacity:0;transform:translateY(-4px)}to{opacity:1;transform:translateY(0)}}.ytdl-closing{opacity:0;transform:translateY(-4px);transition:opacity .15s,transform .15s}@media(prefers-reduced-motion:reduce){#ytdl-menu{animation:none!important;transition:none!important}}';
+  document.documentElement.append(style); attach();
+})();

extension/downloader.html

@@ -0,0 +1,108 @@
+<!doctype html>
+<html lang="ru">
+<head>
+  <meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>YouTubeDL</title><script src="theme-init.js"></script><link rel="stylesheet" href="styles.css">
+</head>
+<body>
+  <main class="app">
+    <header class="header">
+      <div class="brand"><span class="brand-icon">↓</span><div><strong>YouTubeDL</strong><span>Видео. Звук. Ваш выбор.</span></div></div>
+      <div class="header-tools"><button id="open-setup" class="icon-button help-button" title="Настройка и подсказки" aria-label="Открыть мастер настройки">?</button><button id="theme" class="icon-button" title="Тема: автоматически" aria-label="Сменить тему">◐</button><button id="close" class="icon-button embedded-only" title="Закрыть меню" aria-label="Закрыть">×</button></div>
+    </header>
+    <details id="helper-panel" class="helper-panel" data-state="checking">
+      <summary><span class="helper-indicator"><span class="status-dot"></span><span id="helper-status" role="status" aria-live="polite">Проверяем помощник…</span></span><span class="helper-chevron">⌄</span></summary>
+      <div class="helper-body">
+        <p id="helper-message">Проверяю связь с локальным помощником.</p>
+        <p id="helper-versions" class="version-status" role="status"></p>
+        <div class="helper-actions"><button id="helper-start" type="button" class="small-button">Запустить</button><button id="helper-update" type="button" class="small-button" hidden>Обновить компоненты</button><a id="helper-install" class="small-button" href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest" target="_blank" rel="noopener noreferrer">Скачать помощник</a><button id="helper-remove" type="button" class="small-button danger-button" disabled>Удалить</button></div>
+        <label class="auto-update" id="auto-update-row" hidden><input id="auto-update" type="checkbox"><span>Обновлять компоненты автоматически</span></label>
+        <p id="update-note" class="hint" hidden>Проверка раз в сутки, пока помощник работает. Обновления устанавливаются между загрузками.</p>
+        <p id="helper-install-note" class="hint" hidden>На странице релизов проекта скачайте YouTubeDL-Helper-Setup.exe и запустите его. Все компоненты уже внутри. Затем вернитесь сюда и нажмите «Запустить».</p>
+        <details class="dependencies"><summary class="dependency-heading">Состав комплекта <span id="dependencies-status">Ещё не проверен</span></summary><div id="dependencies"></div></details>
+      </div>
+    </details>
+    <section id="session-panel" class="session-panel" data-state="checking" aria-label="Вход в YouTube">
+      <div class="session-heading"><span class="session-dot"></span><span id="session-status" role="status" aria-live="polite">Проверяем вход в YouTube…</span></div>
+      <p id="session-message" class="hint">Используется вход из этого профиля браузера.</p>
+      <div class="session-actions"><button id="session-enable" type="button" class="small-button">Использовать вход в YouTube</button><button id="session-disable" type="button" class="text-button" hidden>Отключить</button></div>
+    </section>
+    <section class="source">
+      <span class="eyebrow">СЕЙЧАС НА YOUTUBE</span>
+      <h1 id="video-title">Подключаюсь к помощнику…</h1>
+      <p id="video-meta" class="muted">Выберите качество и сохраните ролик в один клик.</p>
+      <div id="manual-url" hidden><label for="url-input">Ссылка на ролик</label><div class="url-row"><input id="url-input" type="url" placeholder="https://www.youtube.com/watch?v=…"><button id="load-url" class="small-button">Открыть</button></div></div>
+    </section>
+    <div id="alert" class="alert" role="alert" hidden></div>
+    <div id="error-actions" class="error-actions" hidden><button id="retry-video" type="button" class="small-button">Повторить запрос качества</button></div>
+    <div id="loading" class="loading"><span class="spinner"></span><span id="loading-text">Проверяю подключение…</span></div>
+    <form id="download-form" hidden>
+      <fieldset class="mode-switch" aria-label="Что скачать">
+        <label><input type="radio" name="mode" value="video" checked><span>Видео + звук</span></label>
+        <label><input type="radio" name="mode" value="video_only"><span>Видео</span></label>
+        <label><input type="radio" name="mode" value="audio"><span>Аудио</span></label>
+      </fieldset>
+      <div id="video-options" class="field"><label for="quality">Качество видео <button id="refresh" type="button" class="text-button" title="Обновить дорожки">Обновить</button></label><select id="quality"></select></div>
+      <div id="audio-options" class="field"><label for="audio-quality">Звуковая дорожка</label><select id="audio-quality"></select><p id="audio-note" class="hint">Звук автоматически добавится к видео.</p></div>
+      <div class="two-columns">
+        <div class="field"><label for="container">Формат файла</label><select id="container"></select></div>
+        <div class="field" id="codec-field"><label for="codec">Видеокодек</label><select id="codec"><option value="auto">Авто · быстрее всего</option><option value="copy">Сохранить исходный</option><option value="h264">H.264 · совместимость</option><option value="hevc">HEVC · компактнее</option><option value="av1">AV1 · современный</option><option value="vp9">VP9 · WebM</option></select></div>
+        <div class="field" id="bitrate-field" hidden><label for="bitrate">Битрейт аудио</label><select id="bitrate"><option value="128">128 кбит/с</option><option value="192">192 кбит/с</option><option value="256" selected>256 кбит/с</option><option value="320">320 кбит/с</option></select></div>
+      </div>
+      <details class="advanced"><summary>Ускорение и имя файла <span>⌄</span></summary><div class="advanced-body">
+        <div class="two-columns"><div class="field"><label for="engine">Обработка</label><select id="engine"><option value="auto">Авто · GPU при конвертации</option><option value="nvenc">Только NVIDIA NVENC</option><option value="amf">Только AMD AMF</option><option value="cpu">CPU</option></select></div><div class="field"><label for="preset">Приоритет</label><select id="preset"><option value="fast">Скорость</option><option value="balanced" selected>Баланс</option><option value="quality">Качество</option></select></div></div>
+        <div class="field"><label for="filename">Имя файла <span class="optional">необязательно</span></label><input id="filename" maxlength="150" placeholder="Название ролика"></div>
+      </div></details>
+      <div class="field folder-field"><label for="folder">Сохранить в</label><div class="folder-row"><input id="folder" placeholder="Выберите папку" aria-label="Папка сохранения"><button id="pick-folder" type="button" class="small-button" title="Выбрать папку">Выбрать…</button></div></div>
+      <div class="field folder-field"><label for="work-folder">Рабочая папка для загрузки и обработки</label><div class="folder-row"><input id="work-folder" placeholder="Та же папка, что и для сохранения" aria-label="Рабочая папка"><button id="pick-work-folder" type="button" class="small-button" title="Выбрать диск и рабочую папку">Выбрать…</button></div><p class="hint">Можно выбрать другой диск. Здесь будут дорожки и временные файлы обработки; готовый файл попадёт в папку «Сохранить в». Изменение применяется к следующим загрузкам.</p></div>
+      <div id="processing-hint" class="processing-hint"></div>
+      <div class="form-actions"><button id="save-settings" type="button" class="small-button">Сохранить настройки</button><button id="download" type="submit" class="download-button">Скачать <span id="estimate" class="estimate"></span></button></div>
+    </form>
+    <section id="active-jobs-section" class="jobs-section" hidden><div class="section-label">ТЕКУЩИЕ ОПЕРАЦИИ</div><div id="active-jobs"></div></section>
+    <section class="history-link"><button id="open-history" type="button" class="small-button">История загрузок и ошибок <span aria-hidden="true">↗</span></button><p class="hint">Откроется в новой вкладке.</p></section>
+    <footer><span id="hardware">Видеокарта ещё не проверена</span></footer>
+  </main>
+  <dialog id="setup" class="setup" aria-labelledby="setup-title">
+    <div class="setup-header"><span class="eyebrow">ПЕРВЫЙ ЗАПУСК</span><button id="setup-close" type="button" class="icon-button" aria-label="Пропустить настройку" title="Продолжить позже">×</button></div>
+    <ol class="setup-progress" aria-label="Этапы настройки"><li>Знакомство</li><li>Помощник</li><li>Настройки</li><li>Готово</li></ol>
+    <div class="setup-body">
+      <h2 id="setup-title" tabindex="-1">Сохраняйте ролики в один клик</h2>
+      <section data-setup-step="0">
+        <p>Сначала подключим помощник и выберем, как сохранять видео. Это займёт несколько шагов.</p>
+        <div class="setup-preview" aria-hidden="true"><span class="setup-example-download">↓ Скачать</span><span class="setup-example-settings">⚙</span></div>
+        <p><strong>Загрузчик</strong> использует сохранённые настройки. <strong>«Скачать»</strong> запускает загрузку, а <strong>⚙ рядом</strong> открывает выбор качества, формата и папки.</p>
+        <div class="setup-tip">Кнопки появятся рядом с «Подписаться», на превью роликов и в Shorts.</div>
+      </section>
+      <section data-setup-step="1" hidden>
+        <p>Помощник скачивает дорожки, соединяет видео со звуком и конвертирует файл на вашем компьютере.</p>
+        <div id="setup-helper" class="setup-helper" data-state="checking"><span class="status-dot"></span><strong id="setup-helper-status" role="status" aria-live="polite">Проверяем помощник…</strong></div>
+        <p id="setup-helper-message" class="hint"></p>
+        <p id="setup-versions" class="version-status" role="status"></p>
+        <div class="setup-helper-actions"><a id="setup-install" class="small-button" href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest" target="_blank" rel="noopener noreferrer">Скачать в релизах</a><button id="setup-check" type="button" class="small-button">Проверить подключение</button></div>
+        <ol id="setup-install-steps" class="setup-instructions"><li>На странице релизов проекта скачайте YouTubeDL-Helper-Setup.exe и откройте его из загрузок браузера.</li><li>Дождитесь окончания установки — все компоненты уже внутри.</li><li>Вернитесь сюда и нажмите «Проверить подключение».</li></ol>
+        <p id="setup-gpu" class="setup-tip" hidden></p>
+        <label id="setup-updates-row" class="setup-checkbox" hidden><input id="setup-updates" type="checkbox"><span>Обновлять компоненты автоматически</span></label>
+        <p id="setup-updates-note" class="hint" hidden>Раз в сутки, пока помощник работает, между загрузками. Нужен интернет.</p>
+      </section>
+      <section data-setup-step="2" hidden>
+        <p>Эти настройки будут использоваться кнопками «Скачать» на YouTube. Позже их можно изменить через ⚙.</p>
+        <div class="field"><label for="setup-folder">Куда сохранять файлы</label><div class="folder-row"><input id="setup-folder" placeholder="Выберите папку"><button id="setup-pick-folder" type="button" class="small-button">Выбрать…</button></div></div>
+        <div class="field"><label for="setup-work-folder">Где скачивать и обрабатывать</label><div class="folder-row"><input id="setup-work-folder" placeholder="Та же папка, что и для сохранения"><button id="setup-pick-work-folder" type="button" class="small-button">Выбрать…</button></div><p class="hint">Необязательно: можно выбрать рабочую папку на другом диске.</p></div>
+        <div class="field"><label for="setup-mode">Что скачивать</label><select id="setup-mode"><option value="video">Видео + звук</option><option value="video_only">Только видео</option><option value="audio">Только звук</option></select></div>
+        <div class="two-columns"><div class="field" id="setup-quality-field"><label for="setup-quality">Качество видео</label><select id="setup-quality"><option value="best">Лучшее доступное</option><option value="2160">До 2160p · 4K</option><option value="1440">До 1440p</option><option value="1080">До 1080p · Full HD</option><option value="720">До 720p</option></select></div><div class="field"><label for="setup-format">Формат файла</label><select id="setup-format"></select></div></div>
+        <div class="setup-tip" id="setup-format-hint">Отдельный звук автоматически добавится к видео. Если выбранного качества нет, используем ближайшее доступное.</div>
+        <p class="hint">Обработка — «Авто»: подходящая видеокарта при конвертации, CPU при необходимости. Совместимые дорожки сохраняются без перекодирования.</p>
+      </section>
+      <section data-setup-step="3" hidden>
+        <p id="setup-saved" class="setup-saved"></p>
+        <ol class="setup-instructions"><li><strong>Откройте YouTube.</strong> Если страница была открыта при установке расширения, обновите её.</li><li><strong>Нажмите «Скачать» или ↓ на превью.</strong> Загрузка начнётся по вашим настройкам.</li><li><strong>Следите за уведомлением.</strong> Оно покажет скачивание, объединение дорожек и конвертацию. «Показать файл» откроет результат.</li></ol>
+        <div class="setup-tip">Вход в YouTube необязателен. Если YouTube попросит авторизацию, откройте ⚙ → «Использовать вход в YouTube» и разрешите доступ.</div>
+        <p class="hint">Этот мастер всегда доступен по кнопке ? вверху меню. Кнопка «История загрузок и ошибок» под настройками открывает отдельную вкладку с результатами и сообщениями об ошибках.</p>
+      </section>
+      <p id="setup-error" class="alert" role="alert" hidden></p>
+    </div>
+    <div class="setup-footer"><button id="setup-skip" type="button" class="text-button">Позже</button><div class="setup-navigation"><button id="setup-back" type="button" class="small-button" hidden>Назад</button><button id="setup-next" type="button" class="download-button">Начать настройку</button></div></div>
+  </dialog>
+  <script type="module" src="downloader.js"></script>
+</body>
+</html>

extension/downloader.js

@@ -0,0 +1,454 @@
+import { bytes, canonicalUrl, codecName, duration, progressText, downloadSizeText, processingText, preferenceOptions, errorText, updateText, checkHelperCompatibility } from "./shared.js";
+import { SESSION_PERMISSION } from "./session.js";
+import { createOnboarding } from "./onboarding.js";
+import { createUiConnection } from "./ui-connection.js";
+
+const $ = id => document.getElementById(id);
+const query = new URLSearchParams(location.search);
+const embedded = query.get("embedded") === "1";
+if (embedded) document.documentElement.dataset.embedded = "true";
+let url = canonicalUrl(query.get("url"));
+let metadata = null;
+let hardware = null;
+let preference = {};
+let onboarding = null;
+let theme = "auto";
+let pageTheme = query.get("theme") || "auto";
+let jobStates = {};
+let helper = { status: "checking", message: "Проверяю связь с локальным помощником." };
+let helperBusy = false;
+let busy = false;
+let processingUnavailable = false;
+let sessionBusy = false;
+let session = { status: "checking" };
+const sourceTabId = Number(query.get("tabId")) || null;
+let previousVideoContainer = "mp4";
+let previousAudioContainer = "m4a";
+let previousMode = "video";
+const { call } = createUiConnection({ onEvent: message => {
+  if (message.event === "helper") { renderHelper(message.helper); return; }
+  if (message.event === "remove_job") { delete jobStates[message.jobId]; renderJobs(); return; }
+  if (message.event === "job") { jobStates[message.job.id] = message.job; renderJobs(); return; }
+  if (message.event === "state") { jobStates = Object.fromEntries(message.jobs.map(job => [job.id, job])); renderJobs(); if (message.helper) renderHelper(message.helper); return; }
+}, onDisconnect: () => {
+  renderHelper({ status: "offline", message: "Связь с расширением прервана. Нажмите «Проверить подключение» или «Запустить» — соединение восстановится автоматически." });
+} });
+
+function showError(message) {
+  $("alert").textContent = errorText(message || ""); $("alert").hidden = !message;
+  $("error-actions").hidden = !message || !url || helper.status !== "running" || hardware?.ready === false;
+}
+function renderSession(state = session) {
+  session = state;
+  $("session-panel").dataset.state = state.status;
+  $("session-status").textContent = { checking: "Проверяем вход в YouTube…", connected: "Вход браузера подключён", signed_out: "Вход в YouTube не найден",
+    permission_required: "Нужно разрешение на вход", disabled: "Вход в YouTube не подключён", error: "Не удалось проверить вход" }[state.status];
+  $("session-message").textContent = state.message || "Используется вход из этого профиля браузера.";
+  $("session-enable").textContent = ["connected", "signed_out"].includes(state.status) ? "Проверить вход" : "Использовать вход в YouTube";
+  $("session-enable").disabled = sessionBusy || busy;
+  $("session-disable").hidden = !["connected", "signed_out", "permission_required"].includes(state.status);
+  $("session-disable").disabled = sessionBusy || busy;
+}
+async function refreshSession() {
+  try { renderSession(await call("session_status", { tabId: sourceTabId })); }
+  catch (error) { renderSession({ status: "error", message: error.message }); }
+}
+$("session-enable").addEventListener("click", async () => {
+  if (sessionBusy) return;
+  sessionBusy = true; renderSession(); showError("");
+  try {
+    // Request from the click handler to preserve the browser's user gesture.
+    if (!["connected", "signed_out"].includes(session.status)) {
+      if (!await chrome.permissions.request(SESSION_PERMISSION)) throw new Error("Доступ к входу YouTube не разрешён. Вы можете разрешить его этой кнопкой позднее.");
+      renderSession(await call("session_enable", { enabled: true, tabId: sourceTabId }));
+    } else await refreshSession();
+    if (session.status === "connected" && url && helper.status === "running") await loadVideo();
+  } catch (error) { showError(error.message); }
+  finally { sessionBusy = false; renderSession(); }
+});
+$("session-disable").addEventListener("click", async () => {
+  sessionBusy = true; renderSession();
+  try { renderSession(await call("session_enable", { enabled: false, tabId: sourceTabId })); }
+  catch (error) { showError(error.message); }
+  finally { sessionBusy = false; renderSession(); }
+});
+$("retry-video").addEventListener("click", loadVideo);
+function renderDependencies() {
+  const labels = { python: "Python", yt_dlp: "yt-dlp", ejs: "YouTube JS (EJS)", node: "Node.js", ffmpeg: "FFmpeg + FFprobe" };
+  const measured = helper.status === "running" ? hardware?.dependencies || [] : [];
+  $("dependencies-status").textContent = measured.length ? `${measured.filter(item => item.status === "installed").length}/${measured.length} готовы` : "Ещё не проверены";
+  for (const [id, label] of Object.entries(labels)) {
+    let row = $("dependencies").querySelector(`[data-dependency="${id}"]`);
+    if (!row) {
+      row = document.createElement("div"); row.className = "dependency-row"; row.dataset.dependency = id;
+      row.innerHTML = '<span class="dependency-dot"></span><div class="dependency-copy"><span class="dependency-label"></span><small class="dependency-version"></small></div>';
+      row.querySelector(".dependency-label").textContent = label;
+      $("dependencies").append(row);
+    }
+    const item = measured.find(item => item.id === id);
+    row.dataset.status = item?.status || "unknown";
+    row.querySelector(".dependency-version").textContent = item?.status === "installed" ? item.version || "Установлен" : item?.status === "outdated" ? `${item.version} · нужно обновить` : item ? "Не установлен" : "Проверка после запуска помощника";
+  }
+}
+function renderHelper(state = helper) {
+  if (state.status === "running") {
+    const compatibility = checkHelperCompatibility(state.hardware, chrome.runtime.getManifest().version);
+    state = { ...state, compatibility, ...(compatibility.compatible ? {} : { status: "incompatible", message: compatibility.message }) };
+  }
+  const componentsBecameReady = hardware?.ready === false && state.hardware?.ready === true;
+  helper = state;
+  const connected = state.status === "running";
+  const runningJobs = Object.values(jobStates).some(job => job.status === "running");
+  const updating = Object.values(jobStates).some(job => job.kind === "update" && job.status === "running");
+  $("helper-panel").dataset.state = state.status;
+  $("helper-status").textContent = { running: "Помощник работает", checking: "Проверяем помощник…", missing: "Помощник не установлен",
+    offline: "Помощник отключён", error: "Помощник не отвечает", incompatible: "Нужно обновить версии", idle: "Помощник не подключён" }[state.status] || "Помощник не подключён";
+  $("helper-message").textContent = connected && state.hardware?.bundle?.mode === "autonomous"
+    ? "Автономный комплект: компоненты установлены вместе и могут обновляться из интернета." : state.message || "";
+  const helperVersion = state.hardware?.version || state.hardware?.bundle?.version;
+  updateText($("helper-versions"), `Расширение ${chrome.runtime.getManifest().version} · Помощник ${helperVersion || "не проверен"}${connected ? " · Версии совместимы" : ""}`);
+  $("helper-versions").dataset.state = state.status;
+  $("helper-start").textContent = connected || state.status === "incompatible" ? "Проверить" : "Запустить";
+  $("helper-start").disabled = helperBusy || state.status === "checking";
+  $("helper-install").textContent = state.compatibility?.update === "extension" ? "Обновить расширение" : state.compatibility?.update === "helper" ? "Обновить помощник" : connected ? state.hardware?.ready === false ? "Восстановить" : "Переустановить" : "Скачать помощник";
+  $("helper-install").title = state.compatibility?.update === "extension" ? "Откройте релизы, скачайте новое расширение, замените файлы и нажмите «Обновить» на странице расширений браузера." : "Открыть релизы проекта. Скачайте отдельный YouTubeDL-Helper-Setup.exe и запустите его вручную.";
+  const supportsUpdates = connected && state.hardware?.supportsComponentUpdates === true;
+  $("helper-update").hidden = !supportsUpdates;
+  $("helper-update").disabled = helperBusy || busy || runningJobs || state.hardware?.ready === false;
+  $("auto-update-row").hidden = $("update-note").hidden = !supportsUpdates;
+  $("auto-update").disabled = helperBusy || updating;
+  if (supportsUpdates) $("auto-update").checked = state.hardware.updateSettings?.enabled === true;
+  $("helper-install").setAttribute("aria-disabled", String(helperBusy || runningJobs));
+  $("helper-remove").disabled = !connected || helperBusy || runningJobs;
+  $("helper-remove").title = runningJobs ? "Дождитесь завершения загрузок" : "Отключить и удалить регистрацию помощника";
+  if (!connected) {
+    hardware = null;
+    $("download-form").hidden = true;
+    $("hardware").textContent = "Видеокарта ещё не проверена";
+    if (!["idle", "checking"].includes(state.status)) $("helper-panel").open = true;
+  } else {
+    hardware = state.hardware || hardware;
+    const accelerators = [["nvenc", "NVIDIA NVENC"], ["amf", "AMD AMF"]];
+    const checked = accelerators.filter(([key]) => hardware?.[key]?.length).map(([key, name]) => `${name}: ${hardware[key].map(codecName).join(", ")}`);
+    $("hardware").textContent = hardware?.gpu || "Видеокарта не определена";
+    $("hardware").title = checked.length ? `Проверено кодирование: ${checked.join("; ")}` : "Аппаратное кодирование недоступно. Конвертация выполняется на CPU.";
+    for (const [key] of accelerators) {
+      const option = $("engine").querySelector(`[value="${key}"]`);
+      option.disabled = !hardware?.[key]?.length;
+      if (option.disabled && $("engine").value === key) $("engine").value = "auto";
+    }
+    $("download-form").hidden = busy || !metadata || hardware?.ready === false;
+  }
+  $("download").disabled = !connected || helperBusy || busy || hardware?.ready === false || processingUnavailable
+    || Object.values(jobStates).some(job => ["dependency", "update"].includes(job.kind) && job.status === "running");
+  renderDependencies();
+  onboarding?.render();
+  if (metadata) updateHint();
+  if (componentsBecameReady && url && !metadata && !busy && !helperBusy && !onboarding?.isOpen) queueMicrotask(loadVideo);
+}
+function loading(active, message = "Получаю доступное качество…") {
+  busy = active;
+  $("loading").hidden = !active;
+  $("loading-text").textContent = message;
+  $("download-form").hidden = active || !metadata || helper.status !== "running" || hardware?.ready === false;
+  renderSession();
+}
+function applyTheme() {
+  const resolved = theme === "auto" ? pageTheme : theme;
+  if (["light", "dark"].includes(resolved)) document.documentElement.dataset.theme = resolved;
+  else delete document.documentElement.dataset.theme;
+  $("theme").title = `Тема: ${{ auto: "автоматически", light: "светлая", dark: "тёмная" }[theme]}`;
+  $("theme").textContent = { auto: "◐", light: "☀", dark: "☾" }[theme];
+}
+window.addEventListener("message", event => {
+  if (embedded && event.source === parent && /^https:\/\/(www|m)\.youtube\.com$/.test(event.origin) &&
+      event.data?.type === "YTDL_THEME" && ["light", "dark"].includes(event.data.theme)) {
+    pageTheme = event.data.theme; applyTheme();
+  }
+});
+$("theme").addEventListener("click", () => {
+  theme = { auto: "light", light: "dark", dark: "auto" }[theme];
+  chrome.storage.local.set({ theme }); applyTheme();
+});
+$("close").addEventListener("click", () => {
+  if (embedded) chrome.runtime.sendMessage({ type: "CLOSE_MENU" }).catch(error => showError(error.message));
+  else window.close();
+});
+$("open-history").addEventListener("click", () => {
+  call("open_history", { theme: document.documentElement.dataset.theme || "auto" }).catch(error => showError(error.message));
+});
+document.addEventListener("keydown", event => {
+  if (event.key === "Escape" && !event.defaultPrevented && !onboarding?.isOpen) $("close").click();
+});
+function mode() { return document.querySelector('input[name="mode"]:checked').value; }
+function options(select, items) {
+  select.replaceChildren(...items.map(([value, text]) => {
+    const option = document.createElement("option"); option.value = value; option.textContent = text; return option;
+  }));
+}
+function populate() {
+  options($("quality"), [["best", "Лучшее доступное качество"], ...metadata.videos.map(video => [video.id,
+    `${video.height}p${video.fps > 30 ? ` ${Math.round(video.fps)} fps` : ""} · ${codecName(video.codec)}${video.hdr && video.hdr !== "SDR" ? ` · ${video.hdr}` : ""}${video.hasAudio ? " · со звуком" : ""}${video.size ? ` · ≈${bytes(video.size)}` : ""}`])]);
+  options($("audio-quality"), [["best", "Лучшая доступная дорожка"], ...metadata.audios.map(audio => [audio.id,
+    `${codecName(audio.codec)}${audio.bitrate ? ` · ${Math.round(audio.bitrate)} кбит/с` : ""}${audio.language ? ` · ${audio.language}` : ""}${audio.note ? ` · ${audio.note}` : ""}`])]);
+  $("filename").placeholder = metadata.title;
+  const restored = preferenceOptions(metadata, preference);
+  $("quality").value = restored.videoId; $("audio-quality").value = restored.audioId;
+  updateMode();
+}
+function updateMode() {
+  const current = mode();
+  if (previousMode === "audio") previousAudioContainer = $("container").value || previousAudioContainer;
+  else previousVideoContainer = $("container").value || previousVideoContainer;
+  previousMode = current;
+  $("video-options").hidden = current === "audio";
+  $("audio-options").hidden = current === "video_only";
+  $("codec-field").hidden = current === "audio";
+  $("bitrate-field").hidden = current !== "audio";
+  if (current === "audio") {
+    options($("container"), [["m4a", "M4A · AAC"], ["mp3", "MP3"], ["opus", "Opus"], ["flac", "FLAC"], ["wav", "WAV"]]);
+    $("container").value = previousAudioContainer;
+  } else {
+    options($("container"), [["mp4", "MP4"], ["mkv", "MKV"], ["webm", "WebM"]]);
+    $("container").value = previousVideoContainer;
+  }
+  updateHint();
+}
+function updateHint() {
+  if (!metadata) return;
+  const current = mode();
+  const video = $("quality").value === "best" ? metadata.videos[0] : metadata.videos.find(item => item.id === $("quality").value);
+  const audio = $("audio-quality").value === "best" ? metadata.audios[0] : metadata.audios.find(item => item.id === $("audio-quality").value);
+  $("audio-quality").disabled = current === "video" && Boolean(video?.hasAudio);
+  $("audio-note").textContent = current === "audio" ? "Сохраняется только звук." : video?.hasAudio
+    ? "В этой дорожке звук уже есть — он будет сохранён." : "Отдельный звук скачается и автоматически добавится к видео.";
+  const container = $("container").value;
+  const codec = $("codec").value;
+  const isCompatible = container === "mkv" || (container === "mp4" && ["H.264", "HEVC", "AV1"].includes(codecName(video?.codec)))
+    || (container === "webm" && ["VP9", "AV1", "VP8"].includes(codecName(video?.codec)));
+  const outputCodec = codec === "auto" ? container === "webm" ? "av1" : video?.hdr && video.hdr !== "SDR" ? "hevc" : "h264" : codec;
+  const selectedEngine = $("engine").value;
+  const gpuEngine = ["nvenc", "amf"].find(key => ["auto", key].includes(selectedEngine) && hardware?.[key]?.includes(outputCodec)
+    && !(key === "amf" && video?.hdr && video.hdr !== "SDR" && !hardware?.amf10bit?.includes(outputCodec)));
+  const copiesVideo = codec === "copy" || (codec === "auto" && isCompatible);
+  processingUnavailable = current !== "audio" && !copiesVideo && ["nvenc", "amf"].includes(selectedEngine) && !gpuEngine;
+  $("processing-hint").textContent = current === "audio"
+    ? ["flac", "wav"].includes(container) ? "Без дополнительного сжатия. Исходное качество YouTube не повышается." : "Совместимый звук сохраняется без повторного кодирования."
+    : copiesVideo
+      ? "Видео сохранится без перекодирования — быстро и без потери качества." : processingUnavailable
+        ? `Выбранный кодек недоступен в ${selectedEngine === "amf" ? "AMD AMF" : "NVIDIA NVENC"}. Выберите «Авто» или другой кодек.` : gpuEngine
+        ? `При конвертации используется ${gpuEngine === "amf" ? "AMD AMF" : "NVIDIA NVENC"}. Разрешение сохраняется.` : "Конвертация на CPU. Разрешение сохраняется.";
+  const estimate = current === "audio" ? audio?.size : (video?.size || 0) + (current === "video" && !video?.hasAudio ? audio?.size || 0 : 0);
+  $("estimate").textContent = estimate ? `≈ ${bytes(estimate)}` : "";
+  $("bitrate").disabled = ["flac", "wav"].includes(container);
+  $("download").disabled = helper.status !== "running" || helperBusy || busy || hardware?.ready === false || processingUnavailable
+    || Object.values(jobStates).some(job => ["dependency", "update"].includes(job.kind) && job.status === "running");
+}
+async function loadVideo() {
+  if (!url || !hardware || busy || onboarding?.isOpen) return;
+  if (hardware.ready === false) { $("helper-panel").open = true; loading(false); return; }
+  showError(""); loading(true);
+  metadata = null;
+  $("video-title").textContent = "Получаю качество ролика…";
+  $("video-meta").textContent = "Помощник подключён. Запрашиваю доступные дорожки YouTube.";
+  try {
+    metadata = await call("inspect", { url, tabId: sourceTabId, refresh: true });
+    $("video-title").textContent = metadata.title;
+    $("video-meta").textContent = [metadata.channel, duration(metadata.duration)].filter(Boolean).join(" · ");
+    populate();
+  } catch (error) {
+    $("video-title").textContent = helper.status === "running" ? "Не удалось получить качество" : "Подключим локальный помощник";
+    $("video-meta").textContent = helper.status === "running" ? "Помощник подключён. YouTube не вернул дорожки для этого ролика." : "Проверьте состояние помощника выше.";
+    showError(error.message);
+  }
+  finally { loading(false); }
+}
+$("refresh").addEventListener("click", loadVideo);
+$("load-url").addEventListener("click", () => {
+  const candidate = canonicalUrl($("url-input").value);
+  if (!candidate) { showError("Введите ссылку на ролик или Shorts с YouTube."); return; }
+  url = candidate; loadVideo();
+});
+$("pick-folder").addEventListener("click", async () => {
+  $("pick-folder").disabled = true;
+  try {
+    const result = await call("pick_folder", { current: $("folder").value });
+    if (result.folder) { $("folder").value = result.folder; savePreferences(); }
+  } catch (error) { showError(error.message); }
+  finally { $("pick-folder").disabled = false; }
+});
+$("pick-work-folder").addEventListener("click", async () => {
+  $("pick-work-folder").disabled = true;
+  try {
+    const result = await call("pick_folder", { current: $("work-folder").value || $("folder").value });
+    if (result.folder) { $("work-folder").value = result.folder; await savePreferences(); }
+  } catch (error) { showError(error.message); }
+  finally { $("pick-work-folder").disabled = false; }
+});
+function savePreferences() {
+  preference = { folder: $("folder").value, workFolder: $("work-folder").value.trim(), engine: $("engine").value, preset: $("preset").value,
+    videoContainer: previousVideoContainer, audioContainer: previousAudioContainer, bitrate: Number($("bitrate").value),
+    mode: mode(), codec: $("codec").value, videoId: $("quality").value || "best", audioId: $("audio-quality").value || "best", filename: $("filename").value.trim(),
+    quality: $("quality").value === "best" ? null : (() => { const video = metadata?.videos.find(video => video.id === $("quality").value); return video ? { height: video.height, fps: video.fps, codec: codecName(video.codec) } : null; })(),
+    audioLanguage: metadata?.audios.find(audio => audio.id === $("audio-quality").value)?.language || "" };
+  return chrome.storage.local.set({ preferences: preference });
+}
+document.querySelectorAll('input[name="mode"]').forEach(input => input.addEventListener("change", () => { updateMode(); savePreferences(); }));
+for (const id of ["quality", "audio-quality", "codec", "container", "engine", "bitrate", "preset"]) $(id).addEventListener("change", () => {
+  if (id === "container") { if (mode() === "audio") previousAudioContainer = $(id).value; else previousVideoContainer = $(id).value; }
+  updateHint(); savePreferences();
+});
+$("folder").addEventListener("change", savePreferences);
+$("work-folder").addEventListener("change", savePreferences);
+$("filename").addEventListener("change", savePreferences);
+$("save-settings").addEventListener("click", async () => {
+  await savePreferences();
+  if (embedded) await chrome.runtime.sendMessage({ type: "CLOSE_MENU" });
+  else window.close();
+});
+$("download-form").addEventListener("submit", async event => {
+  event.preventDefault(); showError("");
+  if (!metadata) return;
+  if (!$("folder").value.trim()) { showError("Сначала выберите папку сохранения."); return; }
+  $("download").disabled = true;
+  try {
+    await call("download", { url, title: metadata.title, tabId: Number(query.get("tabId")) || null,
+      mode: mode(), videoId: $("quality").value, audioId: $("audio-quality").value,
+      container: $("container").value, codec: $("codec").value, engine: $("engine").value,
+      preset: $("preset").value, bitrate: Number($("bitrate").value), folder: $("folder").value.trim(), workFolder: $("work-folder").value.trim(), filename: $("filename").value.trim() });
+    savePreferences();
+    if (embedded) await chrome.runtime.sendMessage({ type: "CLOSE_MENU" });
+  } catch (error) { showError(error.message); }
+  finally { $("download").disabled = false; }
+});
+
+function renderJobs() {
+  renderHelper();
+  const sorted = Object.values(jobStates).sort((a, b) => (b.createdAt || 0) - (a.createdAt || 0));
+  const active = sorted.filter(job => job.status === "running");
+  const updateJob = sorted.find(job => job.kind === "update");
+  const orderedCards = { "active-jobs": [] };
+  $("update-note").textContent = updateJob?.status === "complete" ? updateJob.result?.title || "Обновление завершено."
+    : updateJob?.status === "error" ? updateJob.error : "Проверка раз в сутки, пока помощник работает. Обновления устанавливаются между загрузками.";
+  $("active-jobs-section").hidden = !active.length;
+  for (const job of active) {
+    let card = document.querySelector(`[data-job-id="${CSS.escape(job.id)}"]`);
+    if (!card) {
+      card = document.createElement("article"); card.className = "job-card"; card.dataset.jobId = job.id;
+      card.innerHTML = '<div class="job-top"><div><div class="job-title"></div><div class="job-stage"></div></div><span class="job-percent"></span></div><div class="progress-track"><div class="progress-fill"></div></div><div class="job-transfer" hidden></div><div class="job-error" hidden></div><div class="job-actions"></div>';
+    }
+    orderedCards["active-jobs"].push(card);
+    if (card.dataset.status !== job.status) card.dataset.status = job.status;
+    updateText(card.querySelector(".job-title"), job.title || "Видео");
+    const extra = job.stage === "downloading" && Number.isFinite(job.speed) && job.speed >= 0 ? ` · ${job.speed === 0 ? "0 МБ" : bytes(job.speed)}/с` : ["merging", "remuxing", "encoding", "audio"].includes(job.stage) && job.speed ? ` · ${job.speed}` : "";
+    updateText(card.querySelector(".job-stage"), progressText(job) + extra);
+    updateText(card.querySelector(".job-percent"), job.status === "complete" ? "✓" : Number.isFinite(job.percent) ? `${Math.round(job.percent)}%` : "");
+    const fill = card.querySelector(".progress-fill");
+    fill.classList.toggle("indeterminate", job.status === "running" && !Number.isFinite(job.percent));
+    const width = `${Number.isFinite(job.percent) ? Math.min(100, Math.max(0, job.percent)) : 0}%`;
+    if (fill.style.width !== width) fill.style.width = width;
+    const transfer = card.querySelector(".job-transfer");
+    let transferText = downloadSizeText(job) || processingText(job);
+    if (["merging", "remuxing", "encoding", "audio"].includes(job.stage) && Number.isFinite(job.eta) && job.eta > 0) transferText += ` · осталось ≈ ${Math.ceil(job.eta)} с`;
+    updateText(transfer, transferText);
+    transfer.hidden = !transfer.textContent;
+    const error = card.querySelector(".job-error"); error.hidden = !job.error; updateText(error, errorText(job.error || ""));
+    const actions = card.querySelector(".job-actions");
+    if (actions.dataset.status !== job.status) {
+      actions.dataset.status = job.status; actions.replaceChildren();
+      if (["running", "complete"].includes(job.status) && job.canCancel !== false && !(["dependency", "update"].includes(job.kind) && job.status === "complete")) {
+        const button = document.createElement("button"); button.type = "button";
+        button.textContent = job.status === "complete" ? "Показать файл ↗" : "Отменить";
+        button.addEventListener("click", () => call(job.status === "complete" ? "reveal" : "cancel", { jobId: job.id }).catch(error => showError(error.message)));
+        actions.append(button);
+      }
+    }
+  }
+  for (const [id, cards] of Object.entries(orderedCards)) {
+    const parent = $(id);
+    for (const card of [...parent.children]) if (!active.some(job => job.id === card.dataset.jobId)) card.remove();
+    cards.forEach((card, index) => {
+      if (parent.children[index] !== card) parent.insertBefore(card, parent.children[index] || null);
+    });
+  }
+}
+
+async function connectHelper(action = "hello") {
+  if (helperBusy) return;
+  helperBusy = true; showError("");
+  renderHelper({ status: "checking", message: "Запускаю и проверяю локальный помощник…" });
+  try {
+    hardware = await call(action);
+    renderHelper({ status: "running", message: "Помощник отвечает. Загрузка и обработка доступны.", hardware });
+    $("folder").value ||= preference.folder || hardware.defaultFolder;
+    loading(false);
+    if (url && !metadata && hardware.ready !== false && !onboarding?.isOpen) await loadVideo();
+    else if (hardware.ready === false) { $("helper-panel").open = true; $("video-title").textContent = "Установим недостающие компоненты"; }
+    else if (!url) $("video-title").textContent = "Какой ролик скачать?";
+  } catch (error) {
+    if (helper.status === "checking") renderHelper({ status: "error", message: error.message });
+    loading(false); if (!metadata) $("video-title").textContent = "Подключим локальный помощник";
+  } finally { helperBusy = false; renderHelper(); }
+}
+$("helper-start").addEventListener("click", () => connectHelper("helper_start"));
+$("helper-update").addEventListener("click", async () => {
+  helperBusy = true; renderHelper(); showError("");
+  try { await call("helper_update", { tabId: sourceTabId, title: "Обновление компонентов" }); }
+  catch (error) { showError(error.message); }
+  finally { helperBusy = false; renderHelper(); }
+});
+$("auto-update").addEventListener("change", async () => {
+  const enabled = $("auto-update").checked;
+  try {
+    const settings = await call("update_settings", { enabled });
+    if (hardware) hardware.updateSettings = settings;
+    renderHelper();
+  } catch (error) { renderHelper(); showError(error.message); }
+});
+$("helper-install").addEventListener("click", () => {
+  $("helper-install-note").hidden = false;
+});
+$("helper-remove").addEventListener("click", async () => {
+  helperBusy = true; renderHelper(); showError("");
+  try {
+    await call("helper_remove");
+    renderHelper({ status: "missing", message: "Помощник удалён. Для установки скачайте и запустите установщик." });
+  } catch (error) { showError(error.message); }
+  finally { helperBusy = false; renderHelper(); }
+});
+const helperTimer = setInterval(async () => {
+  if (!helperBusy && helper.status !== "checking") {
+    try { renderHelper(await call("helper_status")); } catch {}
+  }
+}, 10000);
+window.addEventListener("pagehide", () => clearInterval(helperTimer), { once: true });
+
+function restorePreferences(saved) {
+  preference = saved;
+  $("folder").value = preference.folder || hardware?.defaultFolder || "";
+  $("work-folder").value = preference.workFolder || "";
+  $("engine").value = preference.engine || "auto"; $("preset").value = preference.preset || "balanced";
+  $("codec").value = preference.codec || "auto"; $("filename").value = preference.filename || "";
+  const preferredMode = document.querySelector(`input[name="mode"][value="${["video", "video_only", "audio"].includes(preference.mode) ? preference.mode : "video"}"]`);
+  preferredMode.checked = true; previousMode = mode();
+  $("bitrate").value = String(preference.bitrate || 256);
+  previousVideoContainer = preference.videoContainer || "mp4"; previousAudioContainer = preference.audioContainer || "m4a";
+  options($("container"), mode() === "audio" ? [["m4a", "M4A · AAC"], ["mp3", "MP3"], ["opus", "Opus"], ["flac", "FLAC"], ["wav", "WAV"]]
+    : [["mp4", "MP4"], ["mkv", "MKV"], ["webm", "WebM"]]);
+  $("container").value = mode() === "audio" ? previousAudioContainer : previousVideoContainer;
+  if (metadata) populate(); else updateMode();
+}
+async function init() {
+  const saved = await chrome.storage.local.get(["theme", "preferences", "onboarding"]);
+  theme = saved.theme || "auto"; applyTheme(); restorePreferences(saved.preferences || {});
+  $("manual-url").hidden = Boolean(url);
+  onboarding = createOnboarding({ call, connectHelper: () => connectHelper("helper_start"), getHelper: () => helper,
+    applyPreferences: restorePreferences, onClose: () => { if (url && !metadata && hardware?.ready) loadVideo(); } });
+  $("open-setup").addEventListener("click", () => onboarding.open().catch(error => showError(error.message)));
+  // Existing configured profiles keep their preferences and can open the guide with ?.
+  if ((!saved.onboarding && !saved.preferences?.folder) || query.get("setup") === "1") await onboarding.open();
+  await refreshSession();
+  await connectHelper();
+  if (query.get("notice")) showError(query.get("notice"));
+}
+init();

extension/history.css

@@ -0,0 +1,11 @@
+.history-app{width:min(960px,100%);padding:38px 28px 24px;margin:auto;animation:enter .25s ease-out}
+.history-app .header{margin-bottom:32px}.history-app h1{font-size:32px;letter-spacing:-.8px;margin:0 0 8px;display:block}.history-intro{color:var(--muted);font-size:14px;margin:0 0 26px}
+.history-tabs{display:flex;gap:8px;padding:5px;background:var(--field);border:1px solid var(--line);border-radius:14px;margin-bottom:22px;width:fit-content;max-width:100%}
+.history-tabs button{display:flex;align-items:center;justify-content:center;gap:12px;border:0;border-radius:10px;background:transparent;color:var(--muted);padding:11px 20px;font:600 14px "Segoe UI",Arial,sans-serif;cursor:pointer;transition:background .18s,color .18s,box-shadow .18s}
+.history-tabs button:hover{color:var(--text)}.history-tabs button[aria-selected=true]{color:var(--text);background:var(--panel);box-shadow:0 2px 7px #0002}.history-count{display:inline-grid;place-items:center;min-width:24px;height:24px;border-radius:8px;padding:0 6px;background:var(--field);font-size:12px;font-variant-numeric:tabular-nums}
+.history-app button:focus-visible,.history-app a:focus-visible,[role=tabpanel]:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
+.history-list{display:grid;gap:12px}.history-entry{padding:20px;background:var(--panel);border:1px solid var(--line);border-radius:15px;animation:enter .2s ease-out;min-width:0}.entry-top{display:flex;justify-content:space-between;align-items:flex-start;gap:16px}.entry-title{font-size:15px;margin:0;line-height:1.5;overflow-wrap:anywhere;min-width:0}.entry-status{border-radius:7px;background:var(--field);padding:4px 8px;color:var(--muted);white-space:nowrap;font-size:11px;flex-shrink:0}.history-entry[data-status=complete] .entry-status{color:#27b98a;background:#27b98a14}.history-entry[data-status=error] .entry-status{color:var(--danger);background:color-mix(in srgb,var(--danger) 9%,transparent)}
+.entry-meta>*{min-width:0;max-width:100%;overflow-wrap:anywhere}
+.entry-meta{display:flex;flex-wrap:wrap;gap:5px 16px;color:var(--muted);font-size:12px;margin-top:8px;font-variant-numeric:tabular-nums}.entry-path{font-size:12px;color:var(--muted);overflow-wrap:anywhere;margin:12px 0 0}.entry-error{font:12px/1.65 "Segoe UI",Arial,sans-serif;color:var(--danger);white-space:pre-wrap;overflow-wrap:anywhere;margin:14px 0 0;padding:12px 14px;border-radius:10px;background:color-mix(in srgb,var(--danger) 5%,var(--bg));border:1px solid color-mix(in srgb,var(--danger) 18%,var(--line))}.entry-actions{display:flex;flex-wrap:wrap;align-items:center;gap:12px;margin-top:15px}.entry-actions a{color:var(--accent);font-size:12px;text-decoration:none}.entry-actions a:hover{text-decoration:underline}.entry-actions .small-button{height:34px;font-size:12px;transform:none}
+.history-empty{display:flex;align-items:center;flex-direction:column;text-align:center;padding:60px 24px;border:1px dashed var(--line);border-radius:16px;background:var(--panel)}.empty-symbol{display:grid;place-items:center;width:52px;height:52px;background:var(--field);border-radius:16px;font-size:26px;color:var(--accent);margin-bottom:18px}.history-empty h2{font-size:18px;margin:0 0 8px}.history-empty p{color:var(--muted);max-width:450px;margin:0;font-size:13px;line-height:1.7}.history-footer{margin-top:24px;font-size:12px;line-height:1.7;color:var(--muted);display:block}.history-connection{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-bottom:18px;font-size:12px;color:var(--muted)}#history-alert{margin-bottom:18px}
+@media(max-width:520px){.history-app{padding:22px 16px}.history-app .header{margin-bottom:26px}.history-app h1{font-size:27px}.history-intro{font-size:13px}.history-tabs{width:100%}.history-tabs button{flex:1;padding:10px 12px;gap:9px}.history-entry{padding:16px}.entry-top{flex-direction:column;gap:8px}.entry-title{font-size:14px}.entry-meta{font-size:11px;gap:5px 12px}.history-empty{padding:40px 18px}.history-connection{align-items:flex-start}}

extension/history.html

@@ -0,0 +1,35 @@
+<!doctype html>
+<html lang="ru">
+<head>
+  <meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>История — YouTubeDL</title>
+  <script src="theme-init.js"></script>
+  <link rel="stylesheet" href="styles.css"><link rel="stylesheet" href="history.css">
+</head>
+<body>
+  <main class="history-app">
+    <header class="header">
+      <div class="brand"><span class="brand-icon" aria-hidden="true">↓</span><div><strong>YouTubeDL</strong><span>История на этом устройстве</span></div></div>
+      <button id="theme" type="button" class="icon-button" title="Тема: автоматически" aria-label="Сменить тему">◐</button>
+    </header>
+    <h1>История</h1>
+    <p class="history-intro">Скачанные файлы и сообщения об ошибках — в одном месте.</p>
+    <div class="history-tabs" role="tablist" aria-label="Раздел истории">
+      <button id="downloads-tab" type="button" role="tab" aria-selected="true" aria-controls="downloads-panel"><span>Загрузки</span><span id="downloads-count" class="history-count">0</span></button>
+      <button id="errors-tab" type="button" role="tab" aria-selected="false" aria-controls="errors-panel" tabindex="-1"><span>Ошибки</span><span id="errors-count" class="history-count">0</span></button>
+    </div>
+    <div id="history-alert" class="alert" role="alert" hidden></div>
+    <div id="history-connection" class="history-connection" hidden><span id="history-connection-message" role="status"></span><button id="history-retry" type="button" class="small-button">Повторить</button></div>
+    <section id="downloads-panel" role="tabpanel" aria-labelledby="downloads-tab" tabindex="0">
+      <div id="downloads-empty" class="history-empty"><span class="empty-symbol" aria-hidden="true">↓</span><h2>Загрузок пока нет</h2><p>Здесь появятся завершённые и отменённые скачивания. Текущий прогресс остаётся в уведомлениях и настройках.</p></div>
+      <div id="downloads-list" class="history-list"></div>
+    </section>
+    <section id="errors-panel" role="tabpanel" aria-labelledby="errors-tab" tabindex="0" hidden>
+      <div id="errors-empty" class="history-empty"><span class="empty-symbol" aria-hidden="true">✓</span><h2>Ошибок нет</h2><p>Если загрузка, получение качества или обновление компонентов завершится ошибкой, её сообщение появится здесь.</p></div>
+      <div id="errors-list" class="history-list"></div>
+    </section>
+    <footer class="history-footer">Записи хранятся только на этом устройстве: до 30 последних операций. Наличие записи не гарантирует, что файл остался в прежней папке.</footer>
+  </main>
+  <script type="module" src="history.js"></script>
+</body>
+</html>

extension/history.js

@@ -0,0 +1,153 @@
+import { bytes, canonicalUrl, errorText, updateText } from "./shared.js";
+import { createUiConnection } from "./ui-connection.js";
+
+const $ = id => document.getElementById(id);
+const tabs = [$("downloads-tab"), $("errors-tab")];
+const dateFormat = new Intl.DateTimeFormat("ru-RU", { dateStyle: "medium", timeStyle: "short" });
+let jobs = {};
+let theme = "auto";
+let call;
+let refreshing = false;
+let reconnectTimer;
+let reconnectDelay = 1000;
+
+function showError(message) {
+  updateText($("history-alert"), errorText(message || ""));
+  $("history-alert").hidden = !message;
+}
+function applyTheme() {
+  if (["dark", "light"].includes(theme)) document.documentElement.dataset.theme = theme;
+  else delete document.documentElement.dataset.theme;
+  const label = { auto: "автоматически", light: "светлая", dark: "тёмная" }[theme];
+  $("theme").title = `Тема: ${label}`;
+  $("theme").setAttribute("aria-label", `Сменить тему. Сейчас: ${label}`);
+  updateText($("theme"), { auto: "◐", light: "☀", dark: "☾" }[theme]);
+}
+$("theme").addEventListener("click", () => {
+  theme = { auto: "light", light: "dark", dark: "auto" }[theme];
+  applyTheme();
+  chrome.storage.local.set({ theme }).catch(error => showError(error.message));
+});
+function selectTab(index) {
+  tabs.forEach((tab, position) => {
+    const selected = position === index;
+    tab.setAttribute("aria-selected", String(selected));
+    tab.tabIndex = selected ? 0 : -1;
+    $(tab.getAttribute("aria-controls")).hidden = !selected;
+  });
+}
+tabs.forEach((tab, index) => {
+  tab.addEventListener("click", () => selectTab(index));
+  tab.addEventListener("keydown", event => {
+    const next = { ArrowRight: (index + 1) % tabs.length, ArrowLeft: (index + tabs.length - 1) % tabs.length, Home: 0, End: tabs.length - 1 }[event.key];
+    if (next === undefined) return;
+    event.preventDefault(); selectTab(next); tabs[next].focus();
+  });
+});
+
+function record(job) {
+  const card = document.createElement("article");
+  card.className = "history-entry"; card.dataset.jobId = job.id; card.dataset.status = job.status;
+  card.innerHTML = '<div class="entry-top"><h2 class="entry-title"></h2><span class="entry-status"></span></div><div class="entry-meta"></div><p class="entry-path" hidden></p><pre class="entry-error" hidden></pre><div class="entry-actions" hidden></div>';
+  updateText(card.querySelector(".entry-title"), job.result?.title || job.title || "Скачивание видео");
+  updateText(card.querySelector(".entry-status"), { complete: "Сохранено", cancelled: "Отменено", error: "Ошибка" }[job.status]);
+  const meta = card.querySelector(".entry-meta");
+  if (Number.isFinite(job.createdAt) && job.createdAt > 0) {
+    const date = new Date(job.createdAt * 1000);
+    if (Number.isFinite(date.getTime())) {
+      const time = document.createElement("time"); time.dateTime = date.toISOString(); time.textContent = dateFormat.format(date); meta.append(time);
+    }
+  }
+  for (const text of [({ update: "Обновление компонентов", dependency: "Установка компонента", inspection: "Получение качества" })[job.kind],
+    job.result?.filename, bytes(job.result?.size)]) {
+    if (!text) continue;
+    const span = document.createElement("span"); span.textContent = text; meta.append(span);
+  }
+  const path = card.querySelector(".entry-path");
+  if (job.result?.path) { path.textContent = job.result.path; path.hidden = false; }
+  const error = card.querySelector(".entry-error");
+  if (job.status === "error") { error.textContent = errorText(job.error || "Операция завершилась ошибкой."); error.hidden = false; }
+  const actions = card.querySelector(".entry-actions");
+  if (job.status === "complete" && job.result?.path) {
+    const reveal = document.createElement("button"); reveal.type = "button"; reveal.className = "small-button"; reveal.textContent = "Показать файл";
+    reveal.addEventListener("click", async () => {
+      reveal.disabled = true; showError("");
+      try { await call("reveal", { jobId: job.id }); }
+      catch (error) { showError(error.message); }
+      finally { reveal.disabled = false; }
+    });
+    actions.append(reveal);
+  }
+  const url = canonicalUrl(job.url);
+  if (url) {
+    const link = document.createElement("a"); link.href = url; link.target = "_blank"; link.rel = "noopener noreferrer"; link.textContent = "Открыть на YouTube ↗"; actions.append(link);
+  }
+  actions.hidden = !actions.children.length;
+  return card;
+}
+function render() {
+  const recent = Object.values(jobs).sort((a, b) => (b.createdAt || 0) - (a.createdAt || 0)).slice(0, 30);
+  const groups = {
+    downloads: recent.filter(job => ["complete", "cancelled"].includes(job.status) && (!job.kind || job.kind === "download")),
+    errors: recent.filter(job => job.status === "error"),
+  };
+  for (const [name, entries] of Object.entries(groups)) {
+    updateText($(`${name}-count`), String(entries.length));
+    $(`${name}-empty`).hidden = Boolean(entries.length);
+    const list = $(`${name}-list`);
+    // Terminal records do not have progress animations. Retain cards on unrelated events.
+    const cards = entries.map(job => {
+      const existing = [...list.children].find(card => card.dataset.jobId === job.id);
+      const signature = JSON.stringify(job);
+      if (existing?.dataset.signature === signature) return existing;
+      const card = record(job); card.dataset.signature = signature; return card;
+    });
+    for (const card of [...list.children]) if (!cards.includes(card)) card.remove();
+    cards.forEach((card, index) => { if (list.children[index] !== card) list.insertBefore(card, list.children[index] || null); });
+  }
+}
+function receive(message) {
+  if (message.event === "state") jobs = Object.fromEntries((message.jobs || []).map(job => [job.id, job]));
+  else if (message.event === "job") jobs[message.job.id] = message.job;
+  else if (message.event === "remove_job") delete jobs[message.jobId];
+  else return;
+  render();
+}
+function retryLater() {
+  if (reconnectTimer) return;
+  reconnectTimer = setTimeout(() => { reconnectTimer = null; refresh(); }, reconnectDelay);
+  reconnectDelay = Math.min(30000, reconnectDelay * 2);
+}
+async function refresh() {
+  if (refreshing || !call) return;
+  refreshing = true; $("history-retry").disabled = true;
+  try {
+    const state = await call("state"); receive({ event: "state", ...state });
+    $("history-connection").hidden = true;
+    clearTimeout(reconnectTimer); reconnectTimer = null; reconnectDelay = 1000;
+  } catch (error) {
+    updateText($("history-connection-message"), "Показаны сохранённые записи. Не удалось обновить историю: " + errorText(error.message));
+    $("history-connection").hidden = false;
+    retryLater();
+  } finally { refreshing = false; $("history-retry").disabled = false; }
+}
+$("history-retry").addEventListener("click", refresh);
+async function init() {
+  const saved = await chrome.storage.local.get(["jobs", "theme"]);
+  jobs = saved.jobs || {}; theme = ["dark", "light"].includes(saved.theme) ? saved.theme : "auto";
+  applyTheme(); render();
+  ({ call } = createUiConnection({ onEvent: receive, onDisconnect: () => {
+    updateText($("history-connection-message"), "Связь с расширением прервалась. Сохранённая история остаётся доступна.");
+    $("history-connection").hidden = false;
+    retryLater();
+  } }));
+  chrome.storage.onChanged?.addListener((changes, area) => {
+    if (area !== "local" || !changes.theme) return;
+    theme = ["dark", "light"].includes(changes.theme.newValue) ? changes.theme.newValue : "auto"; applyTheme();
+  });
+  await refresh();
+  // Only re-read local state; opening history never launches the native helper.
+  setInterval(() => { if (!document.hidden) refresh(); }, 20000);
+  document.addEventListener("visibilitychange", () => { if (!document.hidden) refresh(); });
+}
+init().catch(error => showError(error.message));

extension/manifest.json

@@ -0,0 +1,76 @@
+{
+  "manifest_version": 3,
+  "name": "YouTubeDL",
+  "description": "Скачать видео и аудио с YouTube: качество, формат, папка, NVIDIA NVENC и AMD AMF.",
+  "version": "1.4.5",
+  "minimum_chrome_version": "120",
+  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA6bCUFVUmC9OqpL0+/vrQDKEesuiylybHxRWJXfMV7VfctMbDjAQzActxImzMGIviC8PJrCHT86v/erppUhIgqFrSftHVPPWmYbVJ/g6KBu1bRNIG5J1WDUnMO2E4hGNEJQe+6ezqGuGdk659qQOqP5khGbnog9wUs+1nPpolaXbXsUudn5leaxJ0SrdFT9oWjq59bAc7raEKjR1chU9pB9g9alEA8lqpcKUU8j7f/KJC9YvkOlTNEsLXhuLLzcC7Aw/eI3lgBqBLFWIcrEYrBPVFeIlNaVLdl6b8YqAD+eBaT1xdpT6VbGh/d3lf/Vq/TBzTzCplcMO2vIFGDKTNhQIDAQAB",
+  "permissions": [
+    "nativeMessaging",
+    "storage",
+    "notifications",
+    "activeTab"
+  ],
+  "optional_permissions": [
+    "cookies"
+  ],
+  "optional_host_permissions": [
+    "https://*.youtube.com/*"
+  ],
+  "host_permissions": [
+    "https://www.youtube.com/*",
+    "https://m.youtube.com/*",
+    "https://music.youtube.com/*"
+  ],
+  "background": {
+    "service_worker": "background.js",
+    "type": "module"
+  },
+  "action": {
+    "default_title": "Скачать с YouTube",
+    "default_icon": {
+      "16": "icons/16.png",
+      "32": "icons/32.png"
+    }
+  },
+  "icons": {
+    "16": "icons/16.png",
+    "32": "icons/32.png",
+    "48": "icons/48.png",
+    "128": "icons/128.png"
+  },
+  "content_scripts": [
+    {
+      "matches": [
+        "https://www.youtube.com/*",
+        "https://m.youtube.com/*"
+      ],
+      "js": [
+        "controls.js",
+        "content.js"
+      ],
+      "run_at": "document_idle"
+    }
+  ],
+  "web_accessible_resources": [
+    {
+      "resources": [
+        "downloader.html",
+        "downloader.js",
+        "onboarding.js",
+        "ui-connection.js",
+        "theme-init.js",
+        "shared.js",
+        "session.js",
+        "styles.css"
+      ],
+      "matches": [
+        "https://www.youtube.com/*",
+        "https://m.youtube.com/*"
+      ]
+    }
+  ],
+  "content_security_policy": {
+    "extension_pages": "script-src 'self'; object-src 'none'"
+  }
+}

extension/onboarding.js

@@ -0,0 +1,147 @@
+// First-run guidance uses the same native connection and preferences as downloads.
+export function createOnboarding({ call, connectHelper, getHelper, applyPreferences, onClose }) {
+  const $ = id => document.getElementById(id);
+  const dialog = $("setup");
+  let step = 0, working = false, saved = {};
+  let videoFormat = "mp4", audioFormat = "m4a";
+
+  function error(message = "") {
+    $("setup-error").textContent = message;
+    $("setup-error").hidden = !message;
+  }
+  function formats(remember = true) {
+    if (remember && $("setup-format").value) {
+      if ($("setup-format").dataset.mode === "audio") audioFormat = $("setup-format").value;
+      else videoFormat = $("setup-format").value;
+    }
+    const audio = $("setup-mode").value === "audio";
+    const items = audio ? [["m4a", "M4A · AAC"], ["mp3", "MP3"], ["opus", "Opus"], ["flac", "FLAC"], ["wav", "WAV"]]
+      : [["mp4", "MP4"], ["mkv", "MKV"], ["webm", "WebM"]];
+    $("setup-format").replaceChildren(...items.map(([value, label]) => new Option(label, value)));
+    $("setup-format").dataset.mode = audio ? "audio" : "video";
+    $("setup-format").value = audio ? audioFormat : videoFormat;
+    $("setup-quality-field").hidden = audio;
+    $("setup-format-hint").textContent = audio ? "Сохранится только звуковая дорожка. Формат не повышает исходное качество звука."
+      : $("setup-mode").value === "video_only" ? "Сохранится видео без звука. Если выбранного качества нет, используем ближайшее доступное."
+      : "Отдельный звук автоматически добавится к видео. Если выбранного качества нет, используем ближайшее доступное.";
+  }
+  function ready() { const helper = getHelper(); return helper.status === "running" && helper.hardware?.ready === true; }
+  function render() {
+    const helper = getHelper(), hardware = helper.hardware;
+    const checking = helper.status === "checking";
+    $("setup-helper").dataset.state = ready() ? "running" : helper.status;
+    $("setup-helper-status").textContent = ready() ? "Помощник и компоненты готовы" : checking ? "Проверяем помощник…"
+      : helper.status === "incompatible" ? "Нужно обновить версии" : helper.status === "running" ? "Комплект нужно восстановить" : helper.status === "missing" ? "Нужно установить помощник" : "Подключите помощник";
+    const dependencies = hardware?.dependencies || [];
+    $("setup-helper-message").textContent = ready()
+      ? `${dependencies.filter(item => item.status === "installed").length}/${dependencies.length} компонентов готовы. Дополнительные программы устанавливать не нужно.`
+      : helper.message || "Скачайте установщик, установите комплект и проверьте подключение.";
+    const helperVersion = hardware?.version || hardware?.bundle?.version;
+    $("setup-versions").textContent = `Расширение ${chrome.runtime.getManifest().version} · Помощник ${helperVersion || "не проверен"}${ready() ? " · Версии совместимы" : ""}`;
+    $("setup-versions").dataset.state = helper.status;
+    $("setup-install").hidden = ready();
+    $("setup-install-steps").hidden = ready() || helper.compatibility?.update === "extension";
+    $("setup-install").textContent = helper.compatibility?.update === "extension" ? "Обновить расширение" : helper.compatibility?.update === "helper" ? "Обновить помощник" : helper.status === "running" && !ready() ? "Скачать для восстановления" : "Скачать в релизах";
+    $("setup-check").disabled = working || checking;
+    $("setup-pick-folder").disabled = working || !ready();
+    $("setup-pick-work-folder").disabled = working || !ready();
+    $("setup-check").textContent = checking ? "Проверяем…" : "Проверить подключение";
+    $("setup-gpu").hidden = !ready();
+    if (ready()) {
+      const engines = [hardware.nvenc?.length && "NVIDIA NVENC", hardware.amf?.length && "AMD AMF"].filter(Boolean);
+      $("setup-gpu").textContent = `${hardware.gpu || "Видеокарта не определена"}. ${engines.length ? `Проверено ускорение: ${engines.join(", ")}.` : "Ускорение недоступно, конвертация будет выполняться на CPU."}`;
+    }
+    const updates = ready() && hardware.supportsComponentUpdates === true;
+    $("setup-updates-row").hidden = $("setup-updates-note").hidden = !updates;
+    $("setup-updates").disabled = working;
+    if (!working) $("setup-updates").checked = hardware?.updateSettings?.enabled === true;
+    $("setup-back").hidden = step === 0;
+    $("setup-back").disabled = working;
+    $("setup-next").disabled = working || ([1, 2].includes(step) && !ready());
+    $("setup-next").textContent = ["Начать настройку", "Продолжить", "Сохранить и продолжить", "Готово"][step];
+    $("setup-skip").hidden = step === 3;
+    $("setup-close").disabled = $("setup-skip").disabled = working;
+    // A typed or selected destination is never replaced by a health refresh.
+    if (!$("setup-folder").value && ready()) $("setup-folder").value = saved.folder || hardware.defaultFolder || "";
+  }
+  function showStep(next) {
+    step = next; error();
+    const titles = ["Сохраняйте ролики в один клик", "Подключим локальный помощник", "Выберите настройки скачивания", "Всё готово к скачиванию"];
+    $("setup-title").textContent = titles[step];
+    for (const section of dialog.querySelectorAll("[data-setup-step]")) section.hidden = Number(section.dataset.setupStep) !== step;
+    for (const [index, item] of [...dialog.querySelectorAll(".setup-progress li")].entries()) {
+      item.dataset.state = index < step ? "complete" : index === step ? "current" : "pending";
+      if (index === step) item.setAttribute("aria-current", "step"); else item.removeAttribute("aria-current");
+    }
+    $("setup-saved").textContent = `Файлы будут сохраняться в ${saved.folder || "выбранную папку"}.${saved.workFolder ? ` Загрузка и обработка — в ${saved.workFolder}.` : ""}`;
+    $("setup-title").focus(); $("setup-title").parentElement.scrollTop = 0; render();
+  }
+  async function close(state) {
+    if (working) return;
+    try {
+      await chrome.storage.local.set({ onboarding: { version: 1, state, finishedAt: Date.now() } });
+      dialog.close(); onClose();
+    } catch (failure) { error(`Не удалось сохранить настройку: ${failure.message}`); }
+  }
+  async function run(task) {
+    if (working) return;
+    working = true; error(); render();
+    try { await task(); } catch (failure) { error(failure.message); }
+    finally { working = false; render(); }
+  }
+  $("setup-check").addEventListener("click", () => run(connectHelper));
+  $("setup-install").addEventListener("click", () => {
+    $("setup-helper-message").textContent = "Скачайте YouTubeDL-Helper-Setup.exe на открывшейся странице релизов проекта, запустите его и вернитесь сюда для проверки подключения.";
+  });
+  $("setup-updates").addEventListener("change", () => {
+    const enabled = $("setup-updates").checked;
+    run(async () => {
+      const settings = await call("update_settings", { enabled });
+      if (getHelper().hardware) getHelper().hardware.updateSettings = settings;
+    });
+  });
+  $("setup-pick-folder").addEventListener("click", () => run(async () => {
+    const result = await call("pick_folder", { current: $("setup-folder").value });
+    if (result.folder) $("setup-folder").value = result.folder;
+  }));
+  $("setup-pick-work-folder").addEventListener("click", () => run(async () => {
+    const result = await call("pick_folder", { current: $("setup-work-folder").value || $("setup-folder").value });
+    if (result.folder) $("setup-work-folder").value = result.folder;
+  }));
+  $("setup-mode").addEventListener("change", () => formats());
+  $("setup-back").addEventListener("click", () => showStep(step - 1));
+  $("setup-next").addEventListener("click", async () => {
+    if (working || ([1, 2].includes(step) && !ready())) return;
+    if (step === 3) { await close("complete"); return; }
+    if (step === 2) {
+      if (!$("setup-folder").value.trim()) { error("Выберите папку для сохранения файлов."); $("setup-folder").focus(); return; }
+      await run(async () => {
+        formats();
+        const quality = $("setup-quality").value;
+        const preferences = { ...saved, folder: $("setup-folder").value.trim(), workFolder: $("setup-work-folder").value.trim(), mode: $("setup-mode").value,
+          videoContainer: videoFormat, audioContainer: audioFormat, codec: "auto", engine: "auto", preset: "balanced",
+          bitrate: saved.bitrate || 256, videoId: quality === "best" ? "best" : "setup-quality", audioId: "best",
+          quality: quality === "best" ? null : { height: Number(quality), fps: 30, codec: "" } };
+        await chrome.storage.local.set({ preferences }); saved = preferences;
+        applyPreferences(preferences); showStep(3);
+      });
+    } else showStep(step + 1);
+  });
+  for (const id of ["setup-close", "setup-skip"]) $(id).addEventListener("click", () => close("skipped"));
+  dialog.addEventListener("cancel", event => { event.preventDefault(); close("skipped"); });
+  return {
+    get isOpen() { return dialog.open; },
+    render,
+    async open() {
+      if (dialog.open) return;
+      const stored = await chrome.storage.local.get("preferences"); saved = stored.preferences || {};
+      videoFormat = saved.videoContainer || "mp4"; audioFormat = saved.audioContainer || "m4a";
+      $("setup-folder").value = saved.folder || getHelper().hardware?.defaultFolder || "";
+      $("setup-work-folder").value = saved.workFolder || "";
+      $("setup-mode").value = ["video", "video_only", "audio"].includes(saved.mode) ? saved.mode : "video";
+      $("setup-quality").value = saved.videoId !== "best" && saved.quality?.height ? String(saved.quality.height) : "best";
+      if (!$("setup-quality").value) $("setup-quality").value = "best";
+      formats(false); dialog.showModal(); showStep(0);
+    },
+  };
+}

extension/session.js

@@ -0,0 +1,22 @@
+// Browser session data stays in memory and is sent only to the local native host.
+export const SESSION_PERMISSION = { permissions: ["cookies"], origins: ["https://*.youtube.com/*"] };
+export const isYouTubeDomain = domain => /^(?:[a-z0-9-]+\.)*youtube\.com$/i.test(String(domain || "").replace(/^\./, ""));
+const loginCookie = /^(?:SAPISID|SID|LOGIN_INFO|__Secure-(?:1P|3P)(?:SID|APISID))$/;
+
+export async function readSession(tabId = null, includeCookies = false) {
+  const { youtubeSession = false } = await chrome.storage.local.get("youtubeSession");
+  if (!youtubeSession) return { status: "disabled", message: "Открытые ролики скачиваются без входа. При необходимости можно подключить текущий профиль браузера." };
+  if (!await chrome.permissions.contains(SESSION_PERMISSION)) return { status: "permission_required", message: "Разрешите расширению использовать вход в YouTube." };
+  const stores = Number.isInteger(tabId) ? await chrome.cookies.getAllCookieStores() : [];
+  const storeId = stores.find(store => store.tabIds.includes(tabId))?.id;
+  if (Number.isInteger(tabId) && !storeId) throw new Error("Не удалось определить профиль вкладки YouTube. Откройте меню заново.");
+  const cookies = (await chrome.cookies.getAll({ domain: "youtube.com", ...(storeId ? { storeId } : {}) }))
+    .filter(cookie => isYouTubeDomain(cookie.domain) && !cookie.partitionKey && cookie.value
+      && (!cookie.expirationDate || cookie.expirationDate > Date.now() / 1000))
+    .map(({ name, value, domain, path, secure, httpOnly, hostOnly, expirationDate }) =>
+      ({ name, value, domain, path, secure, httpOnly, hostOnly, ...(expirationDate ? { expirationDate } : {}) }));
+  const connected = cookies.some(cookie => loginCookie.test(cookie.name));
+  return { status: connected ? "connected" : "signed_out", message: connected
+    ? "Вход браузера передаётся локальному помощнику при каждой загрузке."
+    : "В этом профиле вход не найден. Войдите на YouTube и нажмите «Проверить вход».", ...(includeCookies ? { cookies } : {}) };
+}

extension/shared.js

@@ -0,0 +1,126 @@
+export const HOST_NAME = "com.youtubedl.native";
+export function updateText(node, value) {
+  if (node.textContent === value) return;
+  if (node.childNodes.length === 1 && node.firstChild.nodeType === 3) node.firstChild.data = value;
+  else node.textContent = value;
+}
+export function stabilizeDownloadSpeed(job, previous, now = Date.now()) {
+  if (job.status !== "running" || job.stage !== "downloading") return { ...job, speedUpdatedAt: null };
+  if (Number.isFinite(job.speed) && job.speed >= 0) return { ...job, speedUpdatedAt: now };
+  const recent = previous?.status === "running" && previous.stage === job.stage && previous.track === job.track
+    && Number.isFinite(previous.speed) && previous.speed >= 0 && Number.isFinite(previous.speedUpdatedAt)
+    && now >= previous.speedUpdatedAt && now - previous.speedUpdatedAt < 1500;
+  return { ...job, speed: recent ? previous.speed : null, speedUpdatedAt: recent ? previous.speedUpdatedAt : null };
+}
+export const SUPPORTED_HELPER_VERSION = "1.3.2";
+const MINIMUM_EXTENSION_VERSION = "1.4.5";
+function compareVersions(left, right) {
+  if (![left, right].every(value => typeof value === "string" && /^\d+(?:\.\d+){1,3}$/.test(value))) return null;
+  const a = left.split(".").map(Number), b = right.split(".").map(Number);
+  for (let index = 0; index < Math.max(a.length, b.length); index++) {
+    const difference = (a[index] || 0) - (b[index] || 0);
+    if (difference) return Math.sign(difference);
+  }
+  return 0;
+}
+export function checkHelperCompatibility(hardware, extensionVersion) {
+  const helperVersion = hardware?.version || hardware?.bundle?.version;
+  const helperOrder = compareVersions(helperVersion, SUPPORTED_HELPER_VERSION);
+  const minimumExtension = hardware?.minimumExtensionVersion || MINIMUM_EXTENSION_VERSION;
+  const extensionOrder = compareVersions(extensionVersion, minimumExtension);
+  const versions = { helperVersion: helperVersion || "не определена", extensionVersion };
+  if (helperOrder === null) return { ...versions, compatible: false, update: "helper", message: "Не удалось определить версию помощника. Установите актуальный помощник и проверьте подключение." };
+  if (extensionOrder === null) return { ...versions, compatible: false, update: "extension", message: "Не удалось проверить совместимость версий. Обновите расширение и проверьте подключение." };
+  if (helperOrder < 0) return { ...versions, compatible: false, update: "helper", message: `Помощник ${helperVersion} устарел для расширения ${extensionVersion}. Установите помощник ${SUPPORTED_HELPER_VERSION} и нажмите «Проверить». Обновление компонентов не обновляет сам помощник.` };
+  if (extensionOrder < 0) return { ...versions, compatible: false, update: "extension", message: `Для помощника ${helperVersion} нужно расширение ${minimumExtension} или новее. Обновите расширение и перезагрузите вкладку YouTube.` };
+  if (helperOrder > 0) return { ...versions, compatible: false, update: "extension", message: `Помощник ${helperVersion} новее версии, поддерживаемой расширением ${extensionVersion}. Обновите расширение и перезагрузите вкладку YouTube.` };
+  return { ...versions, compatible: true, update: null, message: "Версии совместимы" };
+}
+export function errorText(message = "") {
+  if (/sign in to confirm|not a bot|cookies.*authentication|login required/i.test(message)) {
+    return "YouTube отклонил запрос загрузчика и просит проверку на бота. Повторите запрос или обновите yt-dlp в компонентах. Дополнительно можно подключить вход кнопкой «Использовать вход в YouTube». Помощник работает; переустановка не нужна.";
+  }
+  return String(message);
+}
+export const STAGES = {
+  preparing: "Подготовка", downloading: "Скачивание", merging: "Объединение дорожек", remuxing: "Подготовка файла", finalizing: "Финализация файла",
+  encoding: "Перекодирование", audio: "Обработка аудио", saving: "Сохранение файла", installing: "Установка", updating: "Обновление компонентов", complete: "Готово", error: "Ошибка", cancelled: "Отменено", cancelling: "Останавливаю обработку",
+};
+export function canonicalUrl(value) {
+  try {
+    const url = new URL(value);
+    if (url.protocol !== "https:" || url.username || url.password || (url.port && url.port !== "443")) return null;
+    let id;
+    const parts = url.pathname.split("/").filter(Boolean);
+    if (url.hostname === "youtu.be" && parts.length === 1) id = parts[0];
+    else if (["www.youtube.com", "youtube.com", "m.youtube.com", "music.youtube.com"].includes(url.hostname)) {
+      if (url.pathname === "/watch") id = url.searchParams.get("v");
+      else if (parts.length === 2 && ["shorts", "live", "embed"].includes(parts[0])) id = parts[1];
+    }
+    return /^[\w-]{11}$/.test(id || "") ? `https://www.youtube.com/watch?v=${id}` : null;
+  } catch { return null; }
+}
+export function bytes(value) {
+  if (!Number.isFinite(value) || value <= 0) return "";
+  const units = ["Б", "КБ", "МБ", "ГБ", "ТБ"];
+  const power = Math.min(4, Math.floor(Math.log(value) / Math.log(1024)));
+  return `${(value / 1024 ** power).toLocaleString("ru-RU", { maximumFractionDigits: 1 })} ${units[power]}`;
+}
+export function duration(seconds) {
+  if (!Number.isFinite(seconds) || seconds < 0) return "";
+  const rounded = Math.floor(seconds);
+  return rounded >= 3600 ? `${Math.floor(rounded / 3600)}:${String(Math.floor(rounded / 60) % 60).padStart(2, "0")}:${String(rounded % 60).padStart(2, "0")}`
+    : `${Math.floor(rounded / 60)}:${String(rounded % 60).padStart(2, "0")}`;
+}
+export function codecName(value = "") {
+  if (/^(avc|h264)/i.test(value)) return "H.264";
+  if (/^(hev|hvc|hevc)/i.test(value)) return "HEVC";
+  if (/^(av01|av1)/i.test(value)) return "AV1";
+  if (/^vp0?9/i.test(value)) return "VP9";
+  if (/^(mp4a|aac)/i.test(value)) return "AAC";
+  return value.split(".")[0].toUpperCase();
+}
+export function progressText(job) {
+  const stage = ["updating", "merging", "remuxing", "finalizing", "encoding", "audio"].includes(job.stage) && job.message ? job.message : STAGES[job.stage] || "Обработка";
+  const track = job.stage === "downloading" ? (job.track === "audio" ? " · аудио" : " · видео") : "";
+  const engine = ["encoding", "audio"].includes(job.stage) && job.engine ? ` · ${{ nvenc: "NVIDIA NVENC", amf: "AMD AMF", cpu: "CPU", copy: "без перекодирования" }[job.engine] || job.engine}` : ["merging", "remuxing"].includes(job.stage) && !job.message ? " · без перекодирования" : "";
+  return `${stage}${track}${engine}`;
+}
+
+export function downloadSizeText(job) {
+  const megabytes = value => `${(value / 1048576).toLocaleString("ru-RU", { minimumFractionDigits: 1, maximumFractionDigits: 1 })} МБ`;
+  if (job.status === "complete" && Number.isFinite(job.result?.size) && job.result.size >= 0) return `Размер файла: ${megabytes(job.result.size)}`;
+  const value = job.stage === "saving" ? job.copied : job.downloaded;
+  if (!["downloading", "saving"].includes(job.stage) || !Number.isFinite(value) || value < 0) return "";
+  const downloaded = `${job.stage === "saving" ? "Сохранено" : "Скачано"} ${megabytes(value)}`;
+  return Number.isFinite(job.total) && job.total > 0 ? `${downloaded} из ${megabytes(job.total)}` : downloaded;
+}
+
+export function processingText(job) {
+  if (!["merging", "remuxing", "finalizing", "encoding", "audio"].includes(job.stage)) return "";
+  const parts = [];
+  if (Number.isFinite(job.processedSeconds) && job.processedSeconds >= 0) parts.push(`Обработано ${duration(job.processedSeconds)}${job.durationSeconds > 0 ? ` из ${duration(job.durationSeconds)}` : ""}`);
+  if (Number.isFinite(job.written) && job.written >= 0) parts.push(`Записано ${(job.written / 1048576).toLocaleString("ru-RU", { minimumFractionDigits: 1, maximumFractionDigits: 1 })} МБ`);
+  return parts.join(" · ");
+}
+
+export function preferenceOptions(metadata, preference = {}) {
+  let videoId = preference.videoId || "best", audioId = preference.audioId || "best";
+  const quality = preference.quality;
+  if (videoId !== "best" && quality?.height) {
+    let candidates = metadata.videos.filter(video => video.height <= quality.height);
+    if (!candidates.length) candidates = metadata.videos;
+    candidates = [...candidates].sort((a, b) => b.height - a.height ||
+      (Number(codecName(b.codec) === quality.codec) - Number(codecName(a.codec) === quality.codec)) ||
+      Math.abs(a.fps - (quality.fps || 30)) - Math.abs(b.fps - (quality.fps || 30)));
+    videoId = candidates[0]?.id || "best";
+  } else if (videoId !== "best" && !metadata.videos.some(video => video.id === videoId)) videoId = "best";
+  if (audioId !== "best") {
+    const candidates = preference.audioLanguage ? metadata.audios.filter(audio => audio.language === preference.audioLanguage) : metadata.audios;
+    audioId = candidates.find(audio => audio.id === audioId)?.id || candidates[0]?.id || "best";
+  }
+  const mode = ["video", "video_only", "audio"].includes(preference.mode) ? preference.mode : "video";
+  return { mode, videoId, audioId, container: mode === "audio" ? preference.audioContainer || "m4a" : preference.videoContainer || "mp4",
+    codec: preference.codec || "auto", engine: preference.engine || "auto", preset: preference.preset || "balanced",
+    bitrate: preference.bitrate || 256, folder: preference.folder || "", workFolder: preference.workFolder || "", filename: preference.filename || "" };
+}

extension/styles.css

@@ -0,0 +1,18 @@
+:root{color-scheme:dark;--bg:#15181e;--panel:#1c2028;--field:#232833;--text:#eef1f7;--muted:#939eae;--line:#303847;--accent:#46c3ee;--accent-text:#072330;--danger:#ff9797;--shadow:0 12px 34px #0002}
+@media(prefers-color-scheme:light){:root:not([data-theme=dark]){color-scheme:light;--bg:#fafbfd;--panel:#fff;--field:#f0f3f8;--text:#182234;--muted:#69768a;--line:#dde4ee;--accent:#087eae;--accent-text:#fff;--danger:#ad3030;--shadow:0 8px 24px #142f5010}}
+:root[data-theme=light]{color-scheme:light;--bg:#fafbfd;--panel:#fff;--field:#f0f3f8;--text:#182234;--muted:#69768a;--line:#dde4ee;--accent:#087eae;--accent-text:#fff;--danger:#ad3030;--shadow:0 8px 24px #142f5010}
+*{box-sizing:border-box}html,body{margin:0;min-width:300px;background:var(--bg);color:var(--text);font:13px/1.45 "Segoe UI",Arial,sans-serif}body{transition:background .22s,color .22s}.app{padding:20px 22px 14px;max-width:600px;margin:auto;animation:enter .25s ease-out}.header{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:24px}.brand{display:flex;align-items:center;gap:11px}.brand-icon{display:grid;place-items:center;width:37px;height:39px;border-radius:12px;background:linear-gradient(150deg,#62d6fa,#178aca);color:#073249;font-size:28px;font-weight:700;box-shadow:0 5px 15px #14a4d52b}.brand strong{font-size:18px;letter-spacing:-.6px}.brand div>span{display:block;font-size:11px;color:var(--muted);margin-top:1px}.header-tools{display:flex;gap:4px}.icon-button{border:0;background:none;color:var(--muted);font-size:22px;cursor:pointer;width:31px;height:31px;border-radius:9px;transition:background .15s,transform .15s}.icon-button:hover{background:var(--field);transform:rotate(-8deg)}.source{margin-bottom:18px}.eyebrow,.section-label{color:var(--muted);font-size:9px;letter-spacing:1.8px;font-weight:700}h1{font-size:19px;line-height:1.35;margin:8px 0 6px;letter-spacing:-.45px;overflow-wrap:anywhere;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}.muted{color:var(--muted);margin:0;font-size:12px}.mode-switch{border:1px solid var(--line);padding:4px;display:flex;border-radius:12px;background:var(--field);margin:0 0 17px;gap:4px}.mode-switch label{flex:1;cursor:pointer}.mode-switch input{position:absolute;opacity:0;width:1px;height:1px}.mode-switch span{display:block;text-align:center;font-weight:600;border-radius:8px;padding:9px 2px;color:var(--muted);transition:background .2s,box-shadow .2s,color .2s}.mode-switch input:checked+span{background:var(--panel);color:var(--text);box-shadow:0 2px 7px #0002}.mode-switch input:focus-visible+span{outline:2px solid var(--accent)}.field{margin-bottom:13px;min-width:0}label:not(.mode-switch label){display:flex;align-items:center;justify-content:space-between;gap:6px;margin-bottom:5px;font-size:11px;font-weight:600;color:var(--muted)}input,select{font:inherit;width:100%;height:39px;background:var(--field);color:var(--text);border:1px solid var(--line);border-radius:10px;padding:0 11px;outline:none;transition:border-color .18s,box-shadow .18s}input:focus,select:focus{border-color:var(--accent);box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 15%,transparent)}input::placeholder{color:var(--muted)}select{font-size:12px;padding-right:22px}input:disabled,select:disabled{opacity:.6;cursor:default}.hint{font-size:10px;color:var(--muted);margin:5px 1px 0}.two-columns{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:10px}.text-button{border:0;background:transparent;color:var(--accent);font-size:10px;cursor:pointer;padding:0}.folder-row,.url-row{display:flex;gap:7px;align-items:center}.folder-row input{min-width:0;font-size:11px}.small-button{flex-shrink:0;height:39px;padding:0 12px;border:1px solid var(--line);border-radius:10px;background:var(--panel);color:var(--text);font-size:11px;cursor:pointer;transition:background .15s,transform .15s}.small-button:hover{background:var(--field);transform:translateY(-1px)}.small-button:disabled{opacity:.5;cursor:wait}.advanced{border-top:1px solid var(--line);margin:3px 0 13px;padding-top:10px}.advanced summary{list-style:none;cursor:pointer;color:var(--muted);display:flex;justify-content:space-between;font-size:11px}.advanced summary::-webkit-details-marker{display:none}.advanced summary span{transition:transform .2s}.advanced[open] summary span{transform:rotate(180deg)}.advanced-body{padding-top:11px;animation:enter .2s ease-out}.optional{font-size:10px;font-weight:400;opacity:.7}.processing-hint{font-size:10px;color:var(--muted);margin:8px 0 13px;min-height:15px;line-height:1.5}.download-button{display:flex;justify-content:center;align-items:center;gap:10px;width:100%;height:46px;border:0;border-radius:12px;background:linear-gradient(120deg,var(--accent),color-mix(in srgb,var(--accent) 78%,#126fe5));color:var(--accent-text);font-size:14px;font-weight:700;cursor:pointer;box-shadow:0 5px 18px color-mix(in srgb,var(--accent) 20%,transparent);transition:filter .18s,box-shadow .18s}.download-button:hover{filter:brightness(1.07);box-shadow:0 7px 24px color-mix(in srgb,var(--accent) 30%,transparent)}.download-button:active{filter:brightness(.96)}.download-button:disabled{opacity:.5;cursor:wait;transform:none}.estimate{font-size:10px;opacity:.75;font-weight:400}.alert{border:1px solid color-mix(in srgb,var(--danger) 35%,transparent);background:color-mix(in srgb,var(--danger) 8%,transparent);padding:11px;border-radius:11px;color:var(--danger);font-size:11px;white-space:pre-wrap;overflow-wrap:anywhere;animation:enter .2s ease-out}.loading{display:flex;align-items:center;gap:9px;padding:28px 0;justify-content:center;color:var(--muted);font-size:12px}.spinner{wiLine truncated
+@media(max-width:350px){.app{padding:15px}.two-columns{grid-template-columns:1fr}.brand strong{font-size:16px}.mode-switch span{font-size:11px}.job-title{max-width:190px}}
+@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
+@keyframes spin{to{transform:rotate(360deg)}}@keyframes enter{from{opacity:0;transform:translateY(7px)}to{opacity:1;transform:translateY(0)}}@keyframes shimmer{from{transform:translateX(-100%)}to{transform:translateX(100%)}}@keyframes indeterminate{0%,100%{transform:translateX(0)}50%{transform:translateX(calc(100% / .35 - 100%))}}
+.form-actions{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;align-items:stretch}.form-actions>button{min-width:0;width:100%;height:46px;border-radius:12px;padding:0 12px;font:600 13px "Segoe UI",Arial,sans-serif}.form-actions>.small-button{transform:none}.dependencies{border-top:1px solid var(--line);margin-top:13px;padding-top:11px}.dependency-heading{display:flex;justify-content:space-between;gap:8px;color:var(--muted);font-size:9px;letter-spacing:.7px;margin-bottom:8px}.dependency-heading>span{letter-spacing:0}.dependency-row{display:flex;align-items:center;gap:8px;padding:7px 0}.dependency-dot{width:6px;height:6px;border-radius:50%;background:#8c97a7;flex-shrink:0}.dependency-row[data-status=installed] .dependency-dot{background:#27b98a}.dependency-row[data-status=missing] .dependency-dot{background:#e67d6e}.dependency-row[data-status=outdated] .dependency-dot{background:#dfa942}.dependency-copy{min-width:0;flex:1}.dependency-label{font-size:11px;display:block}.dependency-version{display:block;font-size:9px;color:var(--muted);overflow-wrap:anywhere}.dependency-row button{font-family:inherit;min-width:61px;text-align:right}.dependency-row button:disabled{opacity:.5;cursor:default}@media(max-width:370px){.form-actions{grid-template-columns:1fr}.form-actions>.small-button{order:2}}
+.helper-panel{margin:0 0 15px;padding:9px 11px;border:1px solid var(--line);border-radius:11px;background:var(--panel)}.helper-panel summary{list-style:none;display:flex;align-items:center;justify-content:space-between;gap:10px;cursor:pointer;font-size:11px}.helper-panel summary::-webkit-details-marker{display:none}.helper-indicator{display:flex;align-items:center;gap:7px}.helper-indicator .status-dot{width:7px;height:7px;margin:0;background:#8c97a7;box-shadow:none}.helper-panel[data-state=running] .status-dot{background:#27b98a;box-shadow:0 0 0 3px #27b98a15}.helper-panel[data-state=checking] .status-dot{background:#dfa942}.helper-panel[data-state=missing] .status-dot,.helper-panel[data-state=error] .status-dot{background:#e67d6e}.helper-body{padding-top:9px}.helper-body>p{color:var(--muted);font-size:10px;margin:0 0 10px;overflow-wrap:anywhere}.helper-chevron{color:var(--muted)}.helper-panel[open] .helper-chevron{transform:rotate(180deg)}.helper-actions{display:flex;flex-wrap:wrap;gap:7px}.helper-actions .small-button{height:32px;display:inline-flex;align-items:center;text-decoration:none;font-family:inherit;padding:0 10px}.danger-button{color:var(--danger)}.helper-body #helper-install-note{margin:9px 0 0}footer{line-height:1.6;letter-spacing:0;font-size:10px}
+.session-panel{margin:0 0 18px;padding:11px;border:1px solid var(--line);border-radius:11px;background:var(--panel)}.session-heading{display:flex;gap:8px;align-items:center;font-size:11px;font-weight:600}.session-dot{width:7px;height:7px;border-radius:50%;background:#8c97a7;flex-shrink:0}.session-panel[data-state=connected] .session-dot{background:#27b98a}.session-panel[data-state=signed_out] .session-dot,.session-panel[data-state=permission_required] .session-dot{background:#dfa942}.session-panel[data-state=error] .session-dot{background:#e67d6e}.session-panel .hint{line-height:1.5;margin-top:7px}.session-actions{display:flex;flex-wrap:wrap;align-items:center;gap:12px;margin-top:9px}.session-actions .small-button{height:32px;max-width:100%;white-space:normal;transform:none}.error-actions{margin-top:8px;margin-bottom:15px}
+
+.dependencies>summary{color:var(--muted);font-size:10px;margin-bottom:4px}.dependencies[open]>#dependencies{animation:enter .2s ease-out}.helper-actions a[aria-disabled=true]{pointer-events:none;opacity:.5}
+.history-link{border-top:1px solid var(--line);margin-top:17px;padding-top:14px}.history-link .small-button{display:flex;align-items:center;justify-content:space-between;gap:10px;width:100%;font-family:inherit;font-size:12px;transform:none}.history-link .small-button span{color:var(--accent);font-size:16px}.helper-body label.auto-update{display:flex;justify-content:flex-start;gap:8px;margin:13px 0 0;font-size:11px;font-weight:400;cursor:pointer}.auto-update input{width:15px;height:15px;padding:0;accent-color:var(--accent)}.helper-body #update-note{margin-top:6px}
+.help-button{font-size:17px;font-weight:600}.setup{padding:0;width:min(470px,calc(100% - 24px));max-height:calc(100dvh - 28px);border:1px solid var(--line);border-radius:20px;background:var(--bg);color:var(--text);box-shadow:0 24px 90px #0006;overflow:hidden;font:13px/1.5 "Segoe UI",Arial,sans-serif}.setup[open]{display:flex;flex-direction:column;animation:enter .25s ease-out}.setup::backdrop{background:#080d18a6;backdrop-filter:blur(5px)}.setup-header{display:flex;align-items:center;justify-content:space-between;padding:14px 20px 4px;flex-shrink:0}.setup .icon-button:hover{transform:none}.setup-progress{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:7px;list-style:none;margin:5px 20px 0;padding:0;flex-shrink:0;counter-reset:setup-step}.setup-progress li{counter-increment:setup-step;display:flex;flex-direction:column;align-items:center;gap:6px;padding:10px 0;font-size:10px;color:var(--muted);text-align:center;white-space:nowrap;border-bottom:2px solid var(--line);transition:color .2s,border-color .2s}.setup-progress li:before{content:counter(setup-step);display:grid;place-items:center;width:22px;height:22px;border-radius:50%;background:var(--field);font-size:11px}.setup-progress li[data-state=current]{color:var(--accent);border-color:var(--accent)}.setup-progress li[data-state=current]:before{background:var(--accent);color:var(--accent-text)}.setup-progress li[data-state=complete]:before{content:"✓";color:#27b98a}.setup-body{padding:18px 22px 20px;overflow:auto;min-height:0;overscroll-behavior:contain}.setup h2{font-size:21px;line-height:1.3;letter-spacing:-.4px;margin:0 0 12px;outline:none}.setup-body section{animation:enter .2s ease-out}.setup-body p{margin:10px 0;color:var(--muted)}.setup-body strong{color:var(--text)}.setup-body .hint{font-size:11px}.setup-body .alert{color:var(--danger)}.setup-preview{display:flex;align-items:center;justify-content:center;gap:7px;margin:22px 0}.setup-example-download,.setup-example-settings{display:flex;align-items:center;justify-content:center;border:1px solid var(--line);background:var(--field);border-radius:24px;font-weight:600;height:42px;padding:0 19px;color:var(--text)}.setup-example-settings{font-size:20px;width:42px;padding:0}.setup-tip{padding:12px 13px;background:var(--panel);border:1px solid var(--line);border-left:3px solid var(--accent);border-radius:10px;font-size:12px;margin:15px 0 0;overflow-wrap:anywhere}.setup-instructions{padding-left:21px;color:var(--muted);margin:16px 0}.setup-instructions li{padding-left:3px;margin:10px 0}.setup-helper{display:flex;align-items:center;gap:9px;border:1px solid var(--line);background:var(--panel);border-radius:12px;padding:13px;margin:16px 0 8px}.setup-helper .status-dot{width:7px;height:7px;box-shadow:none;background:#8c97a7;margin:0;flex-shrink:0}.setup-helper[data-state=running] .status-dot{background:#27b98a}.setup-helper[data-state=checking] .status-dot{background:#dfa942}.setup-helper[data-state=missing] .status-dot,.setup-helper[data-state=error] .status-dot{background:#e67d6e}.setup-helper-actions{display:flex;flex-wrap:wrap;gap:8px;margin-top:13px}.setup-helper-actions .small-button{display:inline-flex;align-items:center;text-decoration:none;transform:none;font:inherit;font-size:11px}.setup-body label.setup-checkbox{display:flex;justify-content:flex-start;gap:8px;font-size:12px;font-weight:400;margin:17px 0 0;cursor:pointer}.setup-checkbox input{width:16px;height:16px;padding:0;accent-color:var(--accent);flex-shrink:0}.setup-footer{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:14px 20px;background:var(--panel);border-top:1px solid var(--line);flex-shrink:0}.setup-footer .text-button{font-size:12px}.setup-navigation{display:flex;gap:8px;min-width:0}.setup-navigation .download-button{width:auto;height:40px;padding:0 15px;box-shadow:none;font:600 12px "Segoe UI",Arial,sans-serif}.setup-navigation .small-button{height:40px;transform:none}.setup .field{margin-top:15px}.setup .two-columns .field{margin-top:0}.setup .setup-saved{color:var(--text);overflow-wrap:anywhere}@media(max-width:370px){.setup-header{padding:10px 14px 0}.setup-progress{margin:0 14px;gap:4px}.setup-progress li{font-size:9px}.setup-body{padding:16px}.setup h2{font-size:19px}.setup-footer{padding:12px;gap:7px}.setup-navigation{gap:5px}.setup-navigation .download-button{padding:0 10px;font-size:11px}.setup-navigation .small-button{padding:0 9px;font-size:11px}.setup-footer .text-button{font-size:11px}}
+
+.job-transfer{font-size:12px;color:var(--muted);margin-top:9px;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}
+
+.label,.job-stage{font-variant-numeric:tabular-nums}.version-status{font-size:10px;color:var(--muted);font-variant-numeric:tabular-nums;overflow-wrap:anywhere}.version-status[data-state=incompatible]{color:var(--danger)}.helper-panel[data-state=incompatible] .status-dot,.setup-helper[data-state=incompatible] .status-dot{background:var(--danger)}

extension/theme-init.js

@@ -0,0 +1,3 @@
+// Apply the page theme before the stylesheet paints the embedded menu.
+const initialTheme = new URLSearchParams(location.search).get("theme");
+if (["dark", "light"].includes(initialTheme)) document.documentElement.dataset.theme = initialTheme;

extension/ui-connection.js

@@ -0,0 +1,57 @@
+// A menu can outlive its MV3 service worker while the user runs the installer.
+// Reopen the UI port on the next command; never replay requests already sent.
+export function createUiConnection({ onEvent, onDisconnect, runtime = chrome.runtime }) {
+  const requests = new Map();
+  const disconnected = () => new Error("Связь с расширением прервана. Нажмите «Проверить подключение» или «Запустить» для повторного подключения.");
+  let port = null;
+
+  function drop(connection) {
+    if (port !== connection) return;
+    port = null;
+    for (const [id, request] of requests) {
+      if (request.port !== connection) continue;
+      requests.delete(id); request.reject(disconnected());
+    }
+    onDisconnect?.();
+  }
+  function connect() {
+    if (port) return port;
+    const connection = runtime.connect({ name: "ytdl-ui" });
+    port = connection;
+    connection.onMessage.addListener(message => {
+      if (port !== connection) return;
+      if (message.event) { onEvent?.(message); return; }
+      const request = requests.get(message.id);
+      if (!request || request.port !== connection) return;
+      requests.delete(message.id);
+      message.ok ? request.resolve(message.result) : request.reject(new Error(message.error));
+    });
+    connection.onDisconnect.addListener(() => {
+      // Read lastError in the callback to avoid an unchecked runtime error.
+      void runtime.lastError?.message;
+      drop(connection);
+    });
+    return connection;
+  }
+  function call(action, payload = {}) {
+    return new Promise((resolve, reject) => {
+      for (let attempt = 0; attempt < 2; attempt++) {
+        let connection, id;
+        try {
+          connection = connect(); id = crypto.randomUUID();
+          requests.set(id, { resolve, reject, port: connection });
+          connection.postMessage({ id, action, payload });
+          return;
+        } catch (error) {
+          if (id) requests.delete(id);
+          if (connection) drop(connection);
+          // A synchronous disconnected-port error means this command was not sent.
+          if (attempt === 0 && /disconnected port/i.test(error.message)) continue;
+          reject(/disconnected port/i.test(error.message) ? disconnected() : error);
+          return;
+        }
+      }
+    });
+  }
+  return { call };
+}

host/__init__.py

@@ -0,0 +1 @@
+"""YouTubeDL native messaging helper."""

host/bootstrap.py

@@ -0,0 +1,37 @@
+"""Verify and register an unpacked offline bundle. Never downloads anything."""
+from __future__ import annotations
+import json
+import sys
+from pathlib import Path
+
+from host.bundle import ROOT, executable, manifest
+from host.common import EXTENSION_ID, HOST_NAME
+from host.dependencies import status
+
+
+def verify():
+    if not manifest():
+        raise ValueError("Autonomous bundle metadata is missing.")
+    if Path(sys.executable).resolve() != Path(executable("python")):
+        raise ValueError("The helper must use its embedded Python.")
+    measured = status()
+    if any(item["status"] != "installed" for item in measured):
+        raise ValueError("Bundled components failed verification: " + json.dumps(measured))
+    print(json.dumps({"ready": True, "dependencies": measured}))
+
+
+def configure():
+    verify()
+    runtime = ROOT / ".runtime"
+    runtime.mkdir(exist_ok=True)
+    python = executable("python")
+    launcher = runtime / "launch-host.cmd"
+    launcher.write_bytes((f'@echo off\r\nchcp 65001 >nul\r\nset PYTHONIOENCODING=utf-8\r\nset PYTHONUTF8=1\r\n'
+                          f'set PYTHONDONTWRITEBYTECODE=1\r\n"{python}" -I -X utf8 -B -u "{ROOT / "host" / "main.py"}" %*\r\n').encode("utf-8"))
+    native = {"name": HOST_NAME, "description": "YouTubeDL autonomous helper", "path": str(launcher),
+              "type": "stdio", "allowed_origins": [f"chrome-extension://{EXTENSION_ID}/"]}
+    (runtime / "native-host.json").write_text(json.dumps(native, ensure_ascii=False, indent=2), encoding="utf-8")
+
+
+if __name__ == "__main__":
+    configure() if sys.argv[1:] == ["configure"] else verify()

host/bundle.py

@@ -0,0 +1,49 @@
+"""Application-local runtime; a bundle never falls back to tools on PATH."""
+from __future__ import annotations
+import json
+import os
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+PRODUCT = "YouTubeDL.Helper"
+
+
+def manifest():
+    path = ROOT / "bundle.json"
+    if not path.is_file():
+        return None
+    value = json.loads(path.read_text(encoding="utf-8"))
+    if value.get("product") != PRODUCT or value.get("mode") != "autonomous":
+        raise ValueError("Повреждён комплект помощника. Повторите установку.")
+    return value
+
+
+def executable(name):
+    bundle = manifest()
+    if not bundle:
+        return None
+    relative = bundle.get("tools", {}).get(name)
+    if not isinstance(relative, str):
+        raise ValueError(f"В комплекте отсутствует {name}. Повторите установку помощника.")
+    candidate = (ROOT / relative).resolve()
+    if ROOT not in candidate.parents or not candidate.is_file():
+        raise ValueError(f"Встроенный {name} повреждён. Повторите установку помощника.")
+    return str(candidate)
+
+
+def installation_root():
+    # The installer puts each complete release under <application>/releases/<id>.
+    if manifest() and ROOT.parent.name == "releases":
+        return ROOT.parent.parent
+    return None
+
+
+def history_path():
+    installed = installation_root()
+    return (installed / "data" if installed else ROOT / ".runtime") / "completed-jobs.json"
+
+
+def information():
+    bundle = manifest()
+    return {"mode": "autonomous" if bundle else "source", "version": bundle.get("version") if bundle else None,
+            "updateTogether": bool(bundle)}

host/common.py

@@ -0,0 +1,157 @@
+from __future__ import annotations
+
+import math
+import re
+from pathlib import Path
+from urllib.parse import parse_qs, urlsplit
+
+HOST_NAME = "com.youtubedl.native"
+VERSION = "1.3.2"
+EXTENSION_ID = "ndnoeiaecgmjnjneekaeapeecmmjheli"
+VIDEO_CONTAINERS = {"mp4", "mkv", "webm"}
+AUDIO_CONTAINERS = {"m4a", "mp3", "opus", "flac", "wav"}
+VIDEO_CODECS = {"auto", "copy", "h264", "hevc", "av1", "vp9"}
+ENGINES = {"auto", "nvenc", "amf", "cpu"}
+MODES = {"video", "video_only", "audio"}
+FORMAT_ID = re.compile(r"^[A-Za-z0-9_.-]{1,80}$")
+VIDEO_ID = re.compile(r"^[A-Za-z0-9_-]{11}$")
+
+
+def youtube_url(value: object) -> str:
+    if not isinstance(value, str) or len(value) > 2048:
+        raise ValueError("Нужна ссылка на один ролик YouTube.")
+    try:
+        parsed = urlsplit(value.strip())
+        if parsed.scheme != "https" or parsed.username or parsed.password or parsed.port not in (None, 443):
+            raise ValueError()
+        host = (parsed.hostname or "").lower()
+        parts = parsed.path.strip("/").split("/")
+        if host == "youtu.be" and len(parts) == 1:
+            video_id = parts[0]
+        elif host in {"youtube.com", "www.youtube.com", "m.youtube.com", "music.youtube.com"}:
+            if parsed.path == "/watch":
+                video_id = parse_qs(parsed.query).get("v", [""])[0]
+            elif len(parts) == 2 and parts[0] in {"shorts", "live", "embed"}:
+                video_id = parts[1]
+            else:
+                raise ValueError()
+        else:
+            raise ValueError()
+        if not VIDEO_ID.fullmatch(video_id):
+            raise ValueError()
+    except (ValueError, TypeError):
+        raise ValueError("Поддерживаются HTTPS-ссылки на видео и Shorts с YouTube.") from None
+    return f"https://www.youtube.com/watch?v={video_id}"
+
+
+def format_id(value: object) -> str:
+    if not isinstance(value, str) or not FORMAT_ID.fullmatch(value):
+        raise ValueError("Некорректный идентификатор дорожки.")
+    return value
+
+
+def number(value, default=0):
+    return value if isinstance(value, (int, float)) and math.isfinite(value) else default
+
+
+def video_formats(info: dict) -> list[dict]:
+    return [f for f in info.get("formats", []) if f.get("vcodec") not in (None, "none")
+            and number(f.get("height")) > 0 and not f.get("has_drm") and FORMAT_ID.fullmatch(str(f.get("format_id", "")))]
+
+
+def audio_formats(info: dict) -> list[dict]:
+    return [f for f in info.get("formats", []) if f.get("vcodec") == "none"
+            and f.get("acodec") not in (None, "none") and not f.get("has_drm")
+            and FORMAT_ID.fullmatch(str(f.get("format_id", "")))]
+
+
+def summarize(info: dict) -> dict:
+    if info.get("is_live"):
+        raise ValueError("Дождитесь окончания прямой трансляции. Сейчас поддерживаются готовые ролики.")
+    videos = []
+    for f in reversed(video_formats(info)):
+        videos.append({"id": str(f["format_id"]), "height": number(f.get("height")),
+                       "width": number(f.get("width")), "fps": number(f.get("fps")),
+                       "codec": f.get("vcodec", ""), "extension": f.get("ext", ""),
+                       "hasAudio": f.get("acodec") not in (None, "none"),
+                       "size": number(f.get("filesize") or f.get("filesize_approx")),
+                       "hdr": f.get("dynamic_range", "SDR")})
+    audios = [{"id": str(f["format_id"]), "codec": f.get("acodec", ""),
+               "extension": f.get("ext", ""), "bitrate": number(f.get("abr") or f.get("tbr")),
+               "language": f.get("language") or "", "note": f.get("format_note") or "",
+               "size": number(f.get("filesize") or f.get("filesize_approx"))}
+              for f in reversed(audio_formats(info))]
+    if not videos and not audios:
+        raise ValueError("YouTube не вернул доступных дорожек для этого ролика.")
+    return {"id": str(info.get("id", "")), "url": youtube_url(info.get("webpage_url", "")),
+            "title": str(info.get("title", "Видео"))[:300],
+            "channel": str(info.get("uploader") or info.get("channel") or "")[:200],
+            "duration": number(info.get("duration")), "videos": videos[:180], "audios": audios[:100]}
+
+
+def validate_download(payload: dict) -> dict:
+    if not isinstance(payload, dict):
+        raise ValueError("Некорректная заявка.")
+    mode = payload.get("mode", "video")
+    container = payload.get("container", "mp4")
+    codec = payload.get("codec", "auto")
+    engine = payload.get("engine", "auto")
+    if mode not in MODES or container not in (AUDIO_CONTAINERS if mode == "audio" else VIDEO_CONTAINERS):
+        raise ValueError("Выберите корректный тип загрузки и формат файла.")
+    if codec not in VIDEO_CODECS or engine not in ENGINES or payload.get("preset", "balanced") not in {"fast", "balanced", "quality"}:
+        raise ValueError("Некорректные настройки кодирования.")
+    bitrate = payload.get("bitrate", 256)
+    if isinstance(bitrate, bool) or bitrate not in {128, 192, 256, 320}:
+        raise ValueError("Некорректный битрейт аудио.")
+    folder = payload.get("folder")
+    if not isinstance(folder, str) or not folder or len(folder) > 4096:
+        raise ValueError("Выберите папку сохранения.")
+    path = Path(folder).expanduser()
+    if not path.is_absolute() or not path.is_dir():
+        raise ValueError("Папка сохранения должна существовать и иметь абсолютный путь.")
+    work_folder = payload.get("workFolder", "")
+    if not isinstance(work_folder, str) or len(work_folder) > 4096:
+        raise ValueError("Выберите корректную рабочую папку.")
+    work_folder = work_folder or folder
+    work_path = Path(work_folder).expanduser()
+    if not work_path.is_absolute() or not work_path.is_dir():
+        raise ValueError("Рабочая папка должна существовать и иметь абсолютный путь.")
+    name = payload.get("filename", "")
+    if not isinstance(name, str) or len(name) > 180:
+        raise ValueError("Имя файла слишком длинное.")
+    return {"url": youtube_url(payload.get("url")), "mode": mode, "container": container,
+            "codec": codec, "engine": engine, "preset": payload.get("preset", "balanced"),
+            "bitrate": bitrate, "folder": str(path.resolve()), "workFolder": str(work_path.resolve()), "filename": name,
+            "videoId": format_id(payload.get("videoId", "best")),
+            "audioId": format_id(payload.get("audioId", "best"))}
+
+
+def select_streams(info: dict, options: dict) -> str:
+    videos, audios = video_formats(info), audio_formats(info)
+    def choose(items, wanted, label):
+        if not items:
+            raise ValueError(f"Недоступна дорожка: {label}.")
+        if wanted == "best":
+            return items[-1]
+        for item in items:
+            if str(item["format_id"]) == wanted:
+                return item
+        raise ValueError("Выбранная дорожка исчезла. Обновите список качества.")
+    if options["mode"] == "audio":
+        # A progressive video is a valid fallback when separate audio is absent.
+        return str(choose(audios or [f for f in videos if f.get("acodec") not in (None, "none")],
+                          options["audioId"], "аудио")["format_id"])
+    video = choose(videos, options["videoId"], "видео")
+    if options["mode"] == "video_only" or video.get("acodec") not in (None, "none"):
+        return str(video["format_id"])
+    audio = choose(audios, options["audioId"], "аудио")
+    return f"{video['format_id']}+{audio['format_id']}"
+
+
+def safe_filename(value: str, fallback: str) -> str:
+    value = re.sub(r'[<>:"/\\|?*\x00-\x1f]', "_", value).strip(" .")[:150].rstrip(" .")
+    if not value:
+        value = fallback
+    if value.split(".", 1)[0].upper() in {"CON", "PRN", "AUX", "NUL", *(f"COM{i}" for i in range(1, 10)), *(f"LPT{i}" for i in range(1, 10))}:
+        value = "_" + value
+    return value

host/dependencies.py

@@ -0,0 +1,116 @@
+"""Measured dependency status and isolated installers for the helper."""
+from __future__ import annotations
+import importlib.metadata
+import importlib.util
+import json
+import re
+import subprocess
+import sys
+import tempfile
+import urllib.request
+import zipfile
+from pathlib import Path
+
+from host.media import ROOT, NO_WINDOW, config, run_small, tool
+from host.bundle import manifest
+
+LABELS = {"python": "Python", "yt_dlp": "yt-dlp", "ejs": "YouTube JS (EJS)", "node": "Node.js", "ffmpeg": "FFmpeg + FFprobe"}
+
+
+def status():
+    python_ok = sys.version_info >= (3, 10)
+    result = [{"id": "python", "label": LABELS["python"], "status": "installed" if python_ok else "missing", "version": sys.version.split()[0]}]
+    for key, package in (("yt_dlp", "yt-dlp"), ("ejs", "yt-dlp-ejs")):
+        try:
+            version = importlib.metadata.version(package)
+            result.append({"id": key, "label": LABELS[key], "status": "installed", "version": version})
+        except importlib.metadata.PackageNotFoundError:
+            result.append({"id": key, "label": LABELS[key], "status": "missing", "version": ""})
+    for key in ("node", "ffmpeg"):
+        try:
+            measured = run_small([tool(key), "--version" if key == "node" else "-version"], timeout=8)
+            first = measured.stdout.splitlines()[0] if measured.stdout else ""
+            if measured.returncode != 0 or not first:
+                raise ValueError(f"Version check failed ({measured.returncode}): {measured.stderr[-200:]}")
+            version = first if key == "node" else first.split("version ", 1)[-1].split(" ", 1)[0]
+            installed = int(version.lstrip("v").split(".", 1)[0]) >= 22 if key == "node" else run_small([tool("ffprobe"), "-version"], timeout=8).returncode == 0
+            result.append({"id": key, "label": LABELS[key], "status": "installed" if installed else "outdated", "version": version})
+        except (OSError, ValueError, subprocess.TimeoutExpired) as error:
+            result.append({"id": key, "label": LABELS[key], "status": "missing", "version": "", "message": str(error)[:300]})
+    return result
+
+
+def fetch(url, destination, progress):
+    request = urllib.request.Request(url, headers={"User-Agent": "YouTubeDL-Helper/1.1"})
+    with urllib.request.urlopen(request, timeout=30) as response, destination.open("wb") as output:
+        total = int(response.headers.get("Content-Length", 0)); received = 0
+        while chunk := response.read(1024 * 512):
+            output.write(chunk); received += len(chunk)
+            progress(min(75, received / total * 75) if total else None, "Скачиваю компонент")
+
+
+def extract(archive, folder):
+    root = folder.resolve()
+    with zipfile.ZipFile(archive) as bundle:
+        for entry in bundle.infolist():
+            target = (root / entry.filename).resolve()
+            if target != root and root not in target.parents:
+                raise ValueError("Некорректный путь в архиве компонента.")
+            bundle.extract(entry, root)
+
+
+def install(key, progress, workspace=None):
+    if manifest():
+        raise ValueError("Нажмите «Обновить компоненты» для установки новых версий из интернета или «Восстановить» для переустановки встроенного комплекта.")
+    if key not in {"node", "ffmpeg", "yt_dlp", "ejs"}:
+        raise ValueError("Неизвестный компонент.")
+    runtime = ROOT / ".runtime"
+    runtime.mkdir(exist_ok=True)
+    cfg = config()
+    with tempfile.TemporaryDirectory(prefix=".ytdl-install-", dir=runtime) as temporary:
+        scratch = Path(temporary)
+        if workspace:
+            workspace(str(scratch))
+        if key in {"yt_dlp", "ejs"}:
+            progress(None, "Устанавливаю Python-пакет")
+            package = "yt-dlp[default]>=2026.8.19" if key == "yt_dlp" else "yt-dlp-ejs"
+            measured = subprocess.run([sys.executable, "-m", "pip", "install", "--disable-pip-version-check", "--upgrade", package],
+                                      stdin=subprocess.DEVNULL, capture_output=True, text=True, encoding="utf-8", errors="replace", creationflags=NO_WINDOW, timeout=600)
+            if measured.returncode:
+                raise ValueError("Не удалось установить компонент. " + measured.stderr[-1200:])
+        else:
+            archive = scratch / "component.zip"
+            if key == "node":
+                with urllib.request.urlopen("https://nodejs.org/dist/index.json", timeout=30) as response:
+                    versions = json.load(response)
+                release = next(item["version"] for item in versions if item.get("lts") and "win-x64-zip" in item.get("files", []) and re.fullmatch(r"v\d+\.\d+\.\d+", item["version"]) and int(item["version"].split(".")[0][1:]) >= 22)
+                fetch(f"https://nodejs.org/dist/{release}/node-{release}-win-x64.zip", archive, progress)
+                destination = runtime / "tools" / "node"
+            else:
+                fetch("https://www.gyan.dev/ffmpeg/builds/ffmpeg-release-essentials.zip", archive, progress)
+                destination = runtime / "tools" / "ffmpeg"
+            progress(80, "Распаковываю компонент")
+            extract(archive, destination)
+            # Newer versions may coexist; choose the executable from this archive.
+            with zipfile.ZipFile(archive) as bundle:
+                relative = next(name for name in bundle.namelist() if name.endswith("/node.exe" if key == "node" else "/bin/ffmpeg.exe"))
+            executable = destination / relative
+            cfg[key] = str(executable.resolve())
+            if key == "ffmpeg":
+                cfg["ffprobe"] = str(executable.with_name("ffprobe.exe").resolve())
+        progress(95, "Проверяю компонент")
+        runtime.joinpath("config.json").write_text(json.dumps(cfg, ensure_ascii=False, indent=2), encoding="utf-8")
+        measured = next(item for item in status() if item["id"] == key)
+        if measured["status"] != "installed":
+            raise ValueError("Компонент установлен, но проверка запуска не прошла.")
+        progress(100, "Установка завершена")
+        return {"title": LABELS[key], "dependency": key, "version": measured["version"]}
+
+
+def main():
+    key = sys.argv[1]
+    result = install(key, lambda percent, message: print(f"{message}: {percent if percent is not None else '…'}%", flush=True))
+    print(json.dumps(result, ensure_ascii=False))
+
+
+if __name__ == "__main__": main()

host/ffmpeg_progress.py

@@ -0,0 +1,71 @@
+"""Read FFmpeg's real timeline and output size without blocking stderr."""
+from __future__ import annotations
+
+import math
+import subprocess
+import threading
+from host.media import NO_WINDOW
+
+
+def run_ffmpeg(command, duration, stage, engine, report):
+    duration = float(duration or 0)
+    if not math.isfinite(duration) or duration < 0:
+        duration = 0
+    report(stage=stage, percent=0 if duration else None, engine=engine,
+           speed="", eta=None, processedSeconds=0, durationSeconds=duration, written=0, message="")
+    process = subprocess.Popen(command, stdin=subprocess.DEVNULL, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                               text=True, encoding="utf-8", errors="replace", creationflags=NO_WINDOW)
+    errors, finalizing = [], threading.Event()
+    progress_lock = threading.Lock()
+
+    def read_errors():
+        for line in process.stderr:
+            errors.append(line)
+            if len(errors) > 80:
+                del errors[:40]
+            if "Starting second pass" in line:
+                with progress_lock:
+                    finalizing.set()
+                    report(stage="finalizing", percent=99, engine="copy", speed="", eta=None,
+                           message="Финализация файла")
+
+    reader = threading.Thread(target=read_errors, daemon=True)
+    reader.start()
+    stats = {}
+    elapsed = 0.0
+    try:
+        for raw in process.stdout:
+            key, _, value = raw.strip().partition("=")
+            stats[key] = value
+            if key != "progress":
+                continue
+            try:
+                elapsed = max(elapsed, max(0, int(stats.get("out_time_us", "0")) / 1_000_000))
+            except ValueError:
+                pass
+            speed = stats.get("speed", "")
+            try:
+                rate = float(speed.rstrip("x"))
+            except ValueError:
+                rate = 0
+            eta = max(0, (duration - elapsed) / rate) if duration and rate > 0 and math.isfinite(rate) and not finalizing.is_set() else None
+            try:
+                written = max(0, int(stats.get("total_size", "0")))
+            except ValueError:
+                written = None
+            with progress_lock:
+                is_finalizing = finalizing.is_set()
+                report(stage="finalizing" if is_finalizing else stage, percent=99 if is_finalizing else min(99, elapsed / duration * 100) if duration else None,
+                       engine="copy" if is_finalizing else engine, speed=speed if rate > 0 and math.isfinite(rate) and not is_finalizing else "", eta=None if is_finalizing else eta,
+                       processedSeconds=min(elapsed, duration) if duration else elapsed,
+                       durationSeconds=duration, written=written,
+                       message="Финализация файла" if is_finalizing else "")
+        process.wait()
+        reader.join(timeout=3)
+        return process.returncode, "".join(errors)[-2000:]
+    finally:
+        if process.poll() is None:
+            process.kill()
+            process.wait(timeout=10)
+        for stream in (process.stdout, process.stderr):
+            stream.close()

host/folders.py

@@ -0,0 +1,56 @@
+"""Use the Windows folder picker without shipping Tcl/Tk."""
+from __future__ import annotations
+import base64
+import json
+import os
+import subprocess
+
+
+def pick_folder(current):
+    from host.bundle import installation_root
+    installed = installation_root()
+    if installed:
+        encoded = base64.b64encode(json.dumps(current or "").encode("utf-8")).decode("ascii")
+        result = subprocess.run([str(installed / "YouTubeDL-Manager.exe"), "--pick-folder", "--initial-folder", encoded],
+                                capture_output=True, text=True, encoding="utf-8", errors="replace", timeout=600,
+                                creationflags=subprocess.CREATE_NO_WINDOW)
+        if result.returncode:
+            raise ValueError("Не удалось открыть окно выбора папки Windows.")
+        return json.loads(result.stdout.strip().lstrip("\ufeff"))
+    if os.name != "nt":
+        import tkinter
+        from tkinter import filedialog
+        root = tkinter.Tk()
+        try:
+            root.withdraw(); root.attributes("-topmost", True)
+            return filedialog.askdirectory(initialdir=current or "", mustexist=True) or None
+        finally:
+            root.destroy()
+    # Only base64 data is substituted; paths are never interpolated into shell code.
+    encoded = base64.b64encode(json.dumps(current or "").encode("utf-8")).decode("ascii")
+    script = """
+$ErrorActionPreference='Stop'
+[Console]::OutputEncoding=[Text.UTF8Encoding]::new()
+Add-Type -AssemblyName System.Windows.Forms
+$taskDialog=[Windows.Forms.FolderBrowserDialog]::new()
+$taskOwner=[Windows.Forms.Form]::new()
+try {
+  $taskOwner.TopMost=$true; $taskOwner.ShowInTaskbar=$false; $taskOwner.Opacity=0
+  $taskDialog.Description='YouTubeDL — папка сохранения'
+  $taskDialog.ShowNewFolderButton=$true
+  $taskDialog.SelectedPath=([Text.Encoding]::UTF8.GetString([Convert]::FromBase64String('ENCODED')) | ConvertFrom-Json)
+  $taskOwner.Show()
+  $taskChosen=$null
+  if($taskDialog.ShowDialog($taskOwner) -eq [Windows.Forms.DialogResult]::OK){$taskChosen=$taskDialog.SelectedPath}
+  ConvertTo-Json -InputObject $taskChosen -Compress
+} finally {$taskDialog.Dispose();$taskOwner.Dispose()}
+""".replace("ENCODED", encoded)
+    argument = base64.b64encode(script.encode("utf-16le")).decode("ascii")
+    powershell = os.path.join(os.environ.get("SystemRoot", r"C:\Windows"), "System32", "WindowsPowerShell", "v1.0", "powershell.exe")
+    result = subprocess.run([powershell, "-NoProfile", "-ExecutionPolicy", "Bypass", "-STA", "-EncodedCommand", argument],
+                            capture_output=True, text=True, encoding="utf-8", errors="replace", timeout=600,
+                            creationflags=subprocess.CREATE_NO_WINDOW,
+                            env={**os.environ, "PSModulePath": os.path.join(os.path.dirname(powershell), "Modules")})
+    if result.returncode:
+        raise ValueError("Не удалось открыть окно выбора папки Windows.")
+    return json.loads(result.stdout.strip().lstrip("\ufeff"))

host/installation.py

@@ -0,0 +1,20 @@
+"""Manage only this helper's per-user browser registrations."""
+from pathlib import Path
+from host.common import HOST_NAME
+
+
+def unregister(root: Path):
+    import winreg
+    expected = str((root / ".runtime" / "native-host.json").resolve()).casefold()
+    removed = 0
+    for browser in (r"Google\Chrome", r"Microsoft\Edge", "Chromium"):
+        key = rf"Software\{browser}\NativeMessagingHosts\{HOST_NAME}"
+        try:
+            with winreg.OpenKey(winreg.HKEY_CURRENT_USER, key) as handle:
+                current = winreg.QueryValueEx(handle, "")[0]
+            if isinstance(current, str) and str(Path(current).resolve()).casefold() == expected:
+                winreg.DeleteKey(winreg.HKEY_CURRENT_USER, key)
+                removed += 1
+        except FileNotFoundError:
+            continue
+    return {"removed": True, "registrations": removed}

host/main.py

@@ -0,0 +1,399 @@
+"""Chrome/Edge native messaging host; no listening network port."""
+from __future__ import annotations
+
+import concurrent.futures
+import json
+import os
+import shutil
+import subprocess
+import sys
+import threading
+import time
+import uuid
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from host.common import EXTENSION_ID, VERSION, validate_download, youtube_url
+from host.media import NO_WINDOW, ROOT, capabilities
+from host.protocol import read_message, write_message
+from host.session import validate_cookies
+from host.bundle import history_path, installation_root
+from host.processes import ProcessTree
+
+
+class NativeHost:
+    def __init__(self, output):
+        self.output = output
+        self.output_lock = threading.Lock()
+        self.state_lock = threading.RLock()
+        self.capability_lock = threading.Lock()
+        self.executor = concurrent.futures.ThreadPoolExecutor(max_workers=4)
+        self.history_path = history_path() if installation_root() else ROOT / ".runtime" / "completed-jobs.json"
+        self.jobs = self.read_history()
+        self.processes = {}
+        self.closed = False
+        self._capabilities = None
+        self.picker_lock = threading.Lock()
+        self.auto_timer = None
+        self.auto_candidates = None
+
+    def read_history(self):
+        try:
+            history = json.loads(self.history_path.read_text(encoding="utf-8"))
+            if not isinstance(history, list):
+                return {}
+            return {job["id"]: job for job in history[:30] if isinstance(job, dict)
+                    and isinstance(job.get("id"), str) and job.get("status") == "complete"
+                    and isinstance(job.get("result"), dict) and isinstance(job["result"].get("path"), str)
+                    and Path(job["result"]["path"]).is_absolute()}
+        except (OSError, ValueError):
+            return {}
+
+    def save_history(self):
+        # Keep completed file references so Reveal still works after a browser restart.
+        history = sorted((dict(job) for job in self.jobs.values() if job["status"] == "complete" and job.get("result", {}).get("path")),
+                         key=lambda job: job.get("createdAt", 0), reverse=True)[:30]
+        temporary = self.history_path.with_suffix(".tmp")
+        try:
+            self.history_path.parent.mkdir(parents=True, exist_ok=True)
+            temporary.write_text(json.dumps(history, ensure_ascii=False), encoding="utf-8")
+            os.replace(temporary, self.history_path)
+        except OSError:
+            pass  # Saving a history entry must not fail an otherwise completed download.
+
+    def send(self, message):
+        with self.output_lock:
+            if not self.closed:
+                try:
+                    write_message(self.output, message)
+                except (BrokenPipeError, OSError):
+                    self.closed = True
+
+    def reply(self, request_id, result=None, error=None):
+        self.send({"id": request_id, "ok": error is None, "result": result, "error": error})
+
+    def hardware(self):
+        with self.capability_lock:
+            if self._capabilities is None:
+                self._capabilities = capabilities()
+        return self._capabilities
+
+    def event(self, job_id, **changes):
+        with self.state_lock:
+            state = self.jobs[job_id]
+            if state.get("status") in {"cancelled", "complete", "error"} and changes.get("status") != state.get("status"):
+                return
+            if state.get("cancelling") and changes.get("status") == "complete":
+                return
+            if state.get("cancelling") and changes.get("status") is None and changes.get("stage") != "cancelling":
+                return
+            state.update(changes)
+            state["updatedAt"] = time.time()
+            if changes.get("status") == "complete":
+                self.save_history()
+            snapshot = dict(state)
+        self.send({"event": "job", "job": snapshot})
+
+    def kill(self, process):
+        tree = getattr(process, "ytdl_process_tree", None)
+        if isinstance(tree, ProcessTree):
+            tree.terminate()
+            return
+        if process.poll() is not None:
+            return
+        if os.name == "nt":
+            subprocess.run(["taskkill", "/PID", str(process.pid), "/T", "/F"], stdout=subprocess.DEVNULL,
+                           stderr=subprocess.DEVNULL, creationflags=NO_WINDOW, timeout=15)
+        else:
+            import signal
+            os.killpg(process.pid, signal.SIGTERM)
+
+    def worker(self, action, payload, job_id=None):
+        hardware = self.hardware() if action == "download" else {}
+        encoders = {key: hardware.get(key, []) for key in ("nvenc", "amf", "amf10bit")}
+        # CREATE_SUSPENDED + job assignment happen before even the Python
+        # launcher can create children. stdin is a second gate for the task.
+        process = ProcessTree.launch([sys.executable, "-X", "utf8", "-B", "-u", str(ROOT / "host" / "worker.py")],
+                                   stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                                   text=True, encoding="utf-8", errors="replace", creationflags=NO_WINDOW,
+                                   start_new_session=os.name != "nt")
+        token = job_id or str(uuid.uuid4())
+        with self.state_lock:
+            self.processes[token] = process
+            cancelled = self.closed or (job_id and (self.jobs[job_id]["status"] == "cancelled" or self.jobs[job_id].get("cancelling")))
+        if cancelled:
+            self.kill(process)
+            process.ytdl_process_tree.close()
+            with self.state_lock:
+                self.processes.pop(token, None)
+            return None
+        try:
+            process.stdin.write(json.dumps({"action": action, "payload": payload, "encoders": encoders}) + "\n")
+            process.stdin.close()
+        except BaseException:
+            self.kill(process)
+            process.ytdl_process_tree.close()
+            with self.state_lock:
+                self.processes.pop(token, None)
+            raise
+        errors = []
+        def stderr_reader():
+            for line in process.stderr:
+                errors.append(line)
+                if len(errors) > 40:
+                    del errors[:20]
+        reader = threading.Thread(target=stderr_reader, daemon=True)
+        reader.start()
+        result, error, workspaces = None, None, []
+        workspace_parent = Path(payload.get("workFolder") or payload["folder"]).resolve() if action == "download" else (ROOT / ".runtime").resolve()
+        if action == "helper_update": workspace_parent = (installation_root() / "releases").resolve()
+        workspace_parents = {workspace_parent}
+        if action == "download": workspace_parents.add(Path(payload["folder"]).resolve())
+        try:
+            for line in process.stdout:
+                message = json.loads(line)
+                if message["type"] == "progress" and job_id:
+                    self.event(job_id, **{k: v for k, v in message.items() if k != "type"})
+                elif message["type"] == "result":
+                    result = message["result"]
+                elif message["type"] == "error":
+                    error = message["message"]
+                elif message["type"] == "workspace" and action in {"download", "dependency_install", "helper_update"}:
+                    candidate = Path(message["path"])
+                    if candidate.parent.resolve() in workspace_parents and candidate.name.startswith(".ytdl-") and not candidate.is_symlink():
+                        if candidate not in workspaces: workspaces.append(candidate)
+            process.wait()
+            reader.join(timeout=2)
+            if job_id and (self.jobs[job_id]["status"] == "cancelled" or self.jobs[job_id].get("cancelling")):
+                return None
+            if error or process.returncode or result is None:
+                raise ValueError(error or "Локальный помощник завершился с ошибкой. " + "".join(errors)[-1000:])
+            return result
+        finally:
+            if process.poll() is None:
+                self.kill(process)
+            process.ytdl_process_tree.close()
+            for stream in (process.stdin, process.stdout, process.stderr):
+                stream.close()
+            with self.state_lock:
+                self.processes.pop(token, None)
+            for workspace in workspaces:
+                if not workspace.exists() or workspace.is_symlink() or workspace.resolve().parent not in workspace_parents:
+                    continue
+                retained = False
+                if action == "helper_update":
+                    marker = json.loads((installation_root() / "installation.json").read_text(encoding="utf-8-sig"))
+                    retained = Path(marker["current"]).resolve() == workspace.resolve()
+                if not retained: shutil.rmtree(workspace)
+
+    def run_job(self, job_id, payload, action="download"):
+        try:
+            try:
+                result = self.worker(action, payload, job_id)
+            finally:
+                if action in {"dependency_install", "helper_update"}:
+                    with self.capability_lock:
+                        self._capabilities = None
+            if result is not None:
+                self.event(job_id, status="complete", stage="complete", percent=100, result=result)
+        except Exception as error:
+            with self.state_lock:
+                cancelled = self.jobs[job_id]["status"] == "cancelled" or self.jobs[job_id].get("cancelling")
+            if not cancelled:
+                self.event(job_id, status="error", stage="error", error=str(error)[:2000])
+
+    def start_update(self, candidates=None):
+        if not installation_root(): raise ValueError("Для обновления нужен автономный помощник.")
+        with self.state_lock:
+            if self.processes or any(job["status"] == "running" for job in self.jobs.values()):
+                raise ValueError("Дождитесь завершения текущих операций перед обновлением.")
+            job_id = str(uuid.uuid4())
+            self.jobs[job_id] = {"id": job_id, "status": "running", "stage": "updating", "kind": "update", "title": "Обновление компонентов",
+                                 "percent": None, "createdAt": time.time(), "canCancel": False}
+        self.event(job_id)
+        self.executor.submit(self.run_job, job_id, {"candidates": candidates}, "helper_update")
+        return {"jobId": job_id}
+
+    def schedule_updates(self, delay=30):
+        if self.closed or not installation_root() or self.auto_timer is not None: return
+        self.auto_timer = threading.Timer(delay, self.auto_check)
+        self.auto_timer.daemon = True; self.auto_timer.start()
+
+    def auto_check(self):
+        from host.updates import check_updates, due, settings
+        try:
+            with self.state_lock:
+                if self.closed or self.processes or self._capabilities and self._capabilities.get("ready") is False or any(job["status"] == "running" for job in self.jobs.values()): return
+            if not settings()["enabled"]: self.auto_candidates = None; return
+            if self.auto_candidates is None:
+                if not due(): return
+                self.auto_candidates = check_updates()
+                settings(lastCheck=time.time())
+            with self.state_lock:
+                if self.closed or self.processes or any(job["status"] == "running" for job in self.jobs.values()): return
+                if self.auto_candidates: self.start_update(self.auto_candidates)
+                self.auto_candidates = None
+        except Exception:
+            # Quietly retry a failed automatic metadata check in an hour.
+            try: settings(lastCheck=time.time() - 86400 + 3600)
+            except OSError: pass
+        finally:
+            self.auto_timer = None
+            self.schedule_updates(60)
+    def pick_folder(self, current):
+        from host.folders import pick_folder
+        if not self.picker_lock.acquire(blocking=False):
+            raise ValueError("Диалог выбора папки уже открыт.")
+        try:
+            initial = current if isinstance(current, str) and Path(current).is_dir() else str(Path.home())
+            folder = pick_folder(initial)
+            return {"folder": folder or None}
+        finally:
+            self.picker_lock.release()
+
+    def handle(self, request):
+        request_id = request.get("id")
+        if not isinstance(request_id, str) or len(request_id) > 100:
+            return
+        action, payload = request.get("action"), request.get("payload", {})
+        try:
+            if not isinstance(payload, dict):
+                raise ValueError("Некорректное сообщение.")
+            if action == "hello":
+                from host.updates import settings
+                result = {**self.hardware(), "supportsBrowserCookies": True, "supportsComponentUpdates": bool(installation_root()), "updateSettings": settings()}
+                self.schedule_updates()
+            elif action == "ping":
+                result = {"alive": True, "pid": os.getpid(), "version": VERSION}
+            elif action == "update_settings":
+                from host.updates import settings
+                if not isinstance(payload.get("enabled"), bool): raise ValueError("Некорректная настройка обновлений.")
+                result = settings(payload["enabled"])
+            elif action == "helper_update":
+                result = self.start_update()
+            elif action == "helper_uninstall":
+                with self.state_lock:
+                    if any(job["status"] == "running" for job in self.jobs.values()):
+                        raise ValueError("Дождитесь завершения загрузок перед удалением помощника.")
+                    from host.installation import unregister
+                    result = unregister(ROOT)
+                    installed = installation_root()
+                    if installed and (installed / "YouTubeDL-Manager.exe").is_file():
+                        # The uninstaller outlives the native port. Its output must
+                        # never inherit the browser's native-messaging pipes.
+                        log = installed / "data" / "uninstall.log"
+                        log.parent.mkdir(parents=True, exist_ok=True)
+                        with log.open("wb") as output:
+                            subprocess.Popen([str(installed / "YouTubeDL-Manager.exe"), "--uninstall", "--silent", "--wait-pid", str(os.getpid())],
+                                             stdin=subprocess.DEVNULL, stdout=output, stderr=subprocess.STDOUT,
+                                             close_fds=True, creationflags=NO_WINDOW)
+                        result["uninstallStarted"] = True
+            elif action == "inspect":
+                result = self.worker("inspect", {"url": youtube_url(payload.get("url")), "browserCookies": validate_cookies(payload.get("browserCookies"))})
+            elif action == "pick_folder":
+                result = self.pick_folder(payload.get("current"))
+            elif action == "download":
+                payload = {**validate_download(payload), "browserCookies": validate_cookies(payload.get("browserCookies"))}
+                with self.state_lock:
+                    if any(j["status"] == "running" and j.get("kind") in {"dependency", "update"} for j in self.jobs.values()):
+                        raise ValueError("Дождитесь завершения установки компонентов.")
+                    if sum(j["status"] == "running" for j in self.jobs.values()) >= 2:
+                        raise ValueError("Уже выполняются две загрузки. Дождитесь завершения одной.")
+                    job_id = str(uuid.uuid4())
+                    self.jobs[job_id] = {"id": job_id, "url": payload["url"], "status": "running",
+                                         "stage": "preparing", "percent": None, "createdAt": time.time()}
+                self.reply(request_id, {"jobId": job_id})
+                self.executor.submit(self.run_job, job_id, payload)
+                return
+            elif action == "dependency_install":
+                from host.dependencies import LABELS
+                key = payload.get("dependency")
+                if key not in {"node", "ffmpeg", "yt_dlp", "ejs"}:
+                    raise ValueError("Неизвестный компонент.")
+                with self.state_lock:
+                    if any(job["status"] == "running" for job in self.jobs.values()):
+                        raise ValueError("Дождитесь завершения текущих операций перед установкой компонентов.")
+                    job_id = str(uuid.uuid4())
+                    self.jobs[job_id] = {"id": job_id, "status": "running", "stage": "installing", "kind": "dependency",
+                                         "title": LABELS[key], "percent": None, "createdAt": time.time()}
+                self.reply(request_id, {"jobId": job_id})
+                self.executor.submit(self.run_job, job_id, {"dependency": key}, action)
+                return
+            elif action == "jobs":
+                with self.state_lock:
+                    result = [dict(job) for job in self.jobs.values()]
+            elif action == "cancel":
+                job_id = payload.get("jobId")
+                with self.state_lock:
+                    job = self.jobs.get(job_id)
+                    if not job or job["status"] != "running":
+                        raise ValueError("Эта загрузка уже завершена.")
+                    if job.get("canCancel") is False:
+                        raise ValueError("Дождитесь завершения обновления компонентов.")
+                    self.event(job_id, stage="cancelling", percent=None, cancelling=True, canCancel=False,
+                               speed="", eta=None, message="Останавливаю процессы загрузки и обработки")
+                    process = self.processes.get(job_id)
+                if process:
+                    try:
+                        self.kill(process)
+                    except Exception as error:
+                        self.event(job_id, status="error", stage="error", cancelling=False,
+                                   error="Не удалось остановить процессы: " + str(error))
+                        raise
+                self.event(job_id, status="cancelled", stage="cancelled", percent=None, cancelling=False)
+                result = {"cancelled": True}
+            elif action == "reveal":
+                with self.state_lock:
+                    job = self.jobs.get(payload.get("jobId"))
+                    if not job or job["status"] != "complete":
+                        raise ValueError("Файл ещё не готов.")
+                    path = Path(job["result"]["path"])
+                if not path.is_file():
+                    raise ValueError("Файл был перемещён или удалён.")
+                if os.name == "nt":
+                    subprocess.Popen(["explorer.exe", "/select,", str(path)], creationflags=NO_WINDOW)
+                result = {"shown": True}
+            else:
+                raise ValueError("Неизвестная операция.")
+            self.reply(request_id, result)
+        except Exception as error:
+            self.reply(request_id, error=str(error)[:2000])
+
+    def close(self):
+        self.closed = True
+        if self.auto_timer: self.auto_timer.cancel()
+        with self.state_lock:
+            processes = list(self.processes.values())
+        for process in processes:
+            try:
+                self.kill(process)
+            except (OSError, subprocess.TimeoutExpired):
+                pass
+        self.executor.shutdown(wait=True, cancel_futures=True)
+
+
+def main():
+    if len(sys.argv) > 1 and sys.argv[1] != f"chrome-extension://{EXTENSION_ID}/":
+        print("Недопустимый источник native messaging.", file=sys.stderr)
+        return 1
+    if os.name == "nt":
+        import msvcrt
+        msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
+        msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
+    host = NativeHost(sys.stdout.buffer)
+    try:
+        while (request := read_message(sys.stdin.buffer)) is not None:
+            if request.get("action") in {"cancel", "ping"}:
+                host.handle(request)
+            else:
+                host.executor.submit(host.handle, request)
+    except (EOFError, ValueError, OSError) as error:
+        print(str(error), file=sys.stderr)
+    finally:
+        host.close()
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

host/media.py

@@ -0,0 +1,192 @@
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+from pathlib import Path
+from host.common import VERSION
+from host.bundle import executable, information
+
+ROOT = Path(__file__).resolve().parent.parent
+NO_WINDOW = subprocess.CREATE_NO_WINDOW if os.name == "nt" else 0
+
+
+def config():
+    path = ROOT / ".runtime" / "config.json"
+    return json.loads(path.read_text(encoding="utf-8-sig")) if path.is_file() else {}
+
+
+def tool(name):
+    bundled = executable(name)
+    if bundled:
+        return bundled
+    configured = config().get(name)
+    result = configured if configured and Path(configured).is_file() else shutil.which(name)
+    if not result or not Path(result).is_file():
+        raise ValueError(f"Не найден {name}. Запустите install.ps1.")
+    return str(Path(result).resolve())
+
+
+def run_small(command, timeout=15):
+    return subprocess.run(command, capture_output=True, text=True, encoding="utf-8", errors="replace",
+                          timeout=timeout, creationflags=NO_WINDOW, stdin=subprocess.DEVNULL)
+
+
+def capabilities():
+    from host.dependencies import status
+    dependencies = status()
+    ready = all(item["status"] == "installed" for item in dependencies)
+    ffmpeg = next((item for item in dependencies if item["id"] == "ffmpeg" and item["status"] == "installed"), None)
+    checked = {"nvenc": [], "amf": [], "amf10bit": []}
+    for engine in ("nvenc", "amf"):
+        for codec in ("h264", "hevc", "av1"):
+            if not ffmpeg:
+                break
+            base = [tool("ffmpeg"), "-hide_banner", "-loglevel", "error", "-f", "lavfi", "-i"]
+            preset = ["-preset", "p4"] if engine == "nvenc" else ["-quality", "balanced", "-rc", "cqp", "-qp_i", "20", "-qp_p", "20"]
+            try:
+                result = run_small([*base, "color=c=black:s=640x360:r=30", "-frames:v", "2", "-c:v", f"{codec}_{engine}", *preset, "-f", "null", "-"], timeout=20)
+                if result.returncode == 0:
+                    checked[engine].append(codec)
+                    if engine == "amf" and codec in {"hevc", "av1"}:
+                        extra = ["-profile:v", "main10"] if codec == "hevc" else []
+                        tenbit = run_small([*base, "color=c=black:s=640x360:r=30,format=p010le", "-frames:v", "2", "-c:v", f"{codec}_amf",
+                                           *preset, "-bitdepth", "10", *extra, "-pix_fmt", "+p010le", "-f", "null", "-"], timeout=20)
+                        if tenbit.returncode == 0:
+                            checked["amf10bit"].append(codec)
+            except (OSError, subprocess.TimeoutExpired):
+                continue
+    gpu = ""
+    smi = shutil.which("nvidia-smi")
+    if smi:
+        try:
+            result = run_small([smi, "--query-gpu=name", "--format=csv,noheader"], timeout=8)
+            gpu = result.stdout.strip()[:200] if result.returncode == 0 else ""
+        except (OSError, subprocess.TimeoutExpired):
+            pass
+    if os.name == "nt":
+        try:
+            detected = run_small(["powershell.exe", "-NoProfile", "-Command",
+                                  "[Console]::OutputEncoding=[Text.UTF8Encoding]::new(); "
+                                  "Get-CimInstance Win32_VideoController | Select-Object -ExpandProperty Name"], timeout=10)
+            if detected.returncode == 0:
+                gpu = detected.stdout.strip()[:200] or gpu
+        except (OSError, subprocess.TimeoutExpired):
+            pass
+    return {"version": VERSION, "minimumExtensionVersion": "1.4.5", "supportsWorkFolder": True, "ytDlp": next(item["version"] for item in dependencies if item["id"] == "yt_dlp"), "ffmpeg": ffmpeg["version"] if ffmpeg else "",
+            "gpu": gpu, **checked, "defaultFolder": str(Path.home() / "Downloads"),
+            "dependencies": dependencies, "ready": ready, "bundle": information()}
+
+
+def probe(path):
+    result = run_small([tool("ffprobe"), "-v", "error", "-show_streams", "-show_format", "-of", "json", str(path)], timeout=30)
+    if result.returncode:
+        raise ValueError("FFprobe не смог прочитать загруженный файл.")
+    return json.loads(result.stdout)
+
+
+def encoding_plan(options, media, encoders):
+    # Older development callers supply the NVENC codec list directly.
+    encoders = {"nvenc": encoders} if isinstance(encoders, (list, tuple)) else encoders
+    streams = media.get("streams", [])
+    video = next((s for s in streams if s.get("codec_type") == "video"), None)
+    audio = next((s for s in streams if s.get("codec_type") == "audio"), None)
+    mode, container = options["mode"], options["container"]
+    if mode != "audio" and not video:
+        raise ValueError("В загруженном файле нет видео.")
+    if mode in {"audio", "video"} and not audio:
+        raise ValueError("В загруженном файле нет звуковой дорожки.")
+    if mode == "audio":
+        target = {"m4a": "aac", "mp3": "libmp3lame", "opus": "libopus", "flac": "flac", "wav": "pcm_s16le"}[container]
+        source_audio = audio.get("codec_name")
+        if (container, source_audio) in {("m4a", "aac"), ("mp3", "mp3"), ("opus", "opus"), ("flac", "flac")}:
+            target = "copy"
+        return {"video": None, "audio": target, "engine": "copy" if target == "copy" else "cpu", "hdr": False}
+    source = video.get("codec_name", "")
+    compatible = container == "mkv" or (container == "mp4" and source in {"h264", "hevc", "av1"}) or (container == "webm" and source in {"vp8", "vp9", "av1"})
+    codec = options["codec"]
+    hdr = video.get("color_transfer") in {"smpte2084", "arib-std-b67"}
+    ten_bit = "10" in video.get("pix_fmt", "") or video.get("pix_fmt", "").startswith("p010")
+    if codec == "copy" and not compatible:
+        raise ValueError("Исходный видеокодек несовместим с контейнером. Выберите «Авто» или MKV.")
+    if codec == "auto":
+        codec = "copy" if compatible else ("av1" if container == "webm" else ("hevc" if hdr else "h264"))
+    if container == "webm" and codec not in {"copy", "vp9", "av1"}:
+        raise ValueError("WebM поддерживает AV1 и VP9. Для H.264/HEVC выберите MP4 или MKV.")
+    if hdr and codec == "h264":
+        raise ValueError("Для HDR выберите HEVC, AV1 или сохранение исходного кодека.")
+    engine = "copy" if codec == "copy" else "cpu"
+    if codec != "copy" and options["engine"] != "cpu":
+        for candidate in ("nvenc", "amf"):
+            supported = encoders.get("amf10bit" if candidate == "amf" and ten_bit and codec in {"hevc", "av1"} else candidate, [])
+            if options["engine"] in {"auto", candidate} and codec in supported:
+                engine = candidate
+                break
+        if options["engine"] in {"nvenc", "amf"} and engine != options["engine"]:
+            name = "AMD AMF" if options["engine"] == "amf" else "NVIDIA NVENC"
+            raise ValueError(f"Выбранный кодек или глубина цвета недоступны в {name}. Выберите поддерживаемый кодек или «Авто».")
+    audio_codec = None
+    if mode == "video":
+        ac = audio.get("codec_name", "")
+        if container == "mkv" or (container == "mp4" and ac in {"aac", "mp3", "alac"}) or (container == "webm" and ac in {"opus", "vorbis"}):
+            audio_codec = "copy"
+        else:
+            audio_codec = "libopus" if container == "webm" else "aac"
+    if engine == "copy" and audio_codec not in (None, "copy"):
+        engine = "cpu"
+    return {"video": codec, "audio": audio_codec, "engine": engine, "hdr": hdr, "tenBit": ten_bit}
+
+
+def ffmpeg_command(source, target, options, plan, cuda_decode=True):
+    command = [tool("ffmpeg"), "-hide_banner", "-nostdin", "-loglevel", "info", "-y", "-progress", "pipe:1", "-stats_period", "0.4"]
+    if plan["engine"] == "nvenc" and cuda_decode:
+        command += ["-hwaccel", "cuda"]
+    elif plan["engine"] == "amf" and cuda_decode:
+        command += ["-hwaccel", "d3d11va"]
+    command += ["-i", str(source)]
+    if options["mode"] == "audio":
+        command += ["-map", "0:a:0", "-vn"]
+    else:
+        command += ["-map", "0:v:0"]
+        if options["mode"] == "video":
+            command += ["-map", "0:a:0"]
+        else:
+            command += ["-an"]
+    codec = plan["video"]
+    if codec:
+        if codec == "copy":
+            command += ["-c:v", "copy"]
+        elif plan["engine"] == "nvenc":
+            preset = {"fast": "p2", "balanced": "p4", "quality": "p6"}[options["preset"]]
+            command += ["-c:v", codec + "_nvenc", "-preset", preset, "-rc", "vbr", "-cq", "20", "-b:v", "0"]
+            command += ["-pix_fmt", "p010le" if plan.get("tenBit") and codec in {"hevc", "av1"} else "yuv420p"]
+        elif plan["engine"] == "amf":
+            quality = {"fast": "speed", "balanced": "balanced", "quality": "quality"}[options["preset"]]
+            command += ["-c:v", codec + "_amf", "-quality", quality, "-rc", "cqp", "-qp_i", "20", "-qp_p", "20"]
+            if plan.get("tenBit") and codec in {"hevc", "av1"}:
+                command += ["-bitdepth", "10", "-pix_fmt", "p010le"]
+                if codec == "hevc": command += ["-profile:v", "main10"]
+            else:
+                command += ["-pix_fmt", "yuv420p"]
+        else:
+            encoder = {"h264": "libx264", "hevc": "libx265", "av1": "libsvtav1", "vp9": "libvpx-vp9"}[codec]
+            command += ["-c:v", encoder]
+            if codec in {"h264", "hevc"}:
+                command += ["-preset", {"fast": "veryfast", "balanced": "fast", "quality": "medium"}[options["preset"]], "-crf", "20"]
+            elif codec == "av1":
+                command += ["-preset", "8", "-crf", "24"]
+            else:
+                command += ["-crf", "28", "-b:v", "0", "-row-mt", "1", "-cpu-used", "4"]
+            command += ["-pix_fmt", "yuv420p10le" if plan.get("tenBit") and codec != "h264" else "yuv420p"]
+    if plan["audio"]:
+        command += ["-c:a", plan["audio"]]
+        if plan["audio"] in {"aac", "libmp3lame", "libopus"}:
+            command += ["-b:a", f"{options['bitrate']}k"]
+    command += ["-map_metadata", "0"]
+    if options["container"] in {"mp4", "m4a"}:
+        command += ["-movflags", "+faststart"]
+    if codec == "hevc" and options["container"] == "mp4":
+        command += ["-tag:v", "hvc1"]
+    command += [str(target)]
+    return command

host/processes.py

@@ -0,0 +1,172 @@
+"""Own one worker's process tree, including children left after its exit."""
+from __future__ import annotations
+
+import os
+import subprocess
+import threading
+import time
+
+
+class ProcessTree:
+    @classmethod
+    def launch(cls, command, **kwargs):
+        if os.name == "nt":
+            kwargs["creationflags"] = kwargs.get("creationflags", 0) | 0x4  # CREATE_SUSPENDED
+        else:
+            kwargs["start_new_session"] = True
+        process = subprocess.Popen(command, **kwargs)
+        try:
+            tree = cls(process)
+            process.ytdl_process_tree = tree
+            if os.name == "nt": tree.resume()
+            return process
+        except BaseException:
+            tree = getattr(process, "ytdl_process_tree", None)
+            if tree: tree.close()
+            if process.poll() is None: process.kill()
+            process.wait(timeout=10)
+            for stream in (process.stdin, process.stdout, process.stderr):
+                if stream: stream.close()
+            raise
+
+    def __init__(self, process):
+        self.process = process
+        self.lock = threading.Lock()
+        self.handle = None
+        if os.name != "nt":
+            return
+        import ctypes
+        from ctypes import wintypes
+
+        class BasicLimits(ctypes.Structure):
+            _fields_ = [("ProcessTime", ctypes.c_longlong), ("JobTime", ctypes.c_longlong),
+                        ("Flags", wintypes.DWORD), ("MinWorkingSet", ctypes.c_size_t),
+                        ("MaxWorkingSet", ctypes.c_size_t), ("ActiveLimit", wintypes.DWORD),
+                        ("Affinity", ctypes.c_size_t), ("Priority", wintypes.DWORD), ("Scheduling", wintypes.DWORD)]
+
+        class Limits(ctypes.Structure):
+            _fields_ = [("Basic", BasicLimits), ("Io", ctypes.c_ulonglong * 6),
+                        ("ProcessMemory", ctypes.c_size_t), ("JobMemory", ctypes.c_size_t),
+                        ("PeakProcessMemory", ctypes.c_size_t), ("PeakJobMemory", ctypes.c_size_t)]
+
+        class Accounting(ctypes.Structure):
+            _fields_ = [("Times", ctypes.c_longlong * 4), ("PageFaults", wintypes.DWORD),
+                        ("TotalProcesses", wintypes.DWORD), ("ActiveProcesses", wintypes.DWORD),
+                        ("TerminatedProcesses", wintypes.DWORD)]
+
+        self.ctypes, self.Accounting = ctypes, Accounting
+        self.api = ctypes.WinDLL("kernel32", use_last_error=True)
+        for name, args, result in [
+            ("CreateJobObjectW", [ctypes.c_void_p, wintypes.LPCWSTR], wintypes.HANDLE),
+            ("SetInformationJobObject", [wintypes.HANDLE, ctypes.c_int, ctypes.c_void_p, wintypes.DWORD], wintypes.BOOL),
+            ("QueryInformationJobObject", [wintypes.HANDLE, ctypes.c_int, ctypes.c_void_p, wintypes.DWORD, ctypes.c_void_p], wintypes.BOOL),
+            ("AssignProcessToJobObject", [wintypes.HANDLE, wintypes.HANDLE], wintypes.BOOL),
+            ("TerminateJobObject", [wintypes.HANDLE, wintypes.UINT], wintypes.BOOL),
+            ("OpenProcess", [wintypes.DWORD, wintypes.BOOL, wintypes.DWORD], wintypes.HANDLE),
+            ("CloseHandle", [wintypes.HANDLE], wintypes.BOOL),
+            ("CreateToolhelp32Snapshot", [wintypes.DWORD, wintypes.DWORD], wintypes.HANDLE),
+            ("Thread32First", [wintypes.HANDLE, ctypes.c_void_p], wintypes.BOOL),
+            ("Thread32Next", [wintypes.HANDLE, ctypes.c_void_p], wintypes.BOOL),
+            ("OpenThread", [wintypes.DWORD, wintypes.BOOL, wintypes.DWORD], wintypes.HANDLE),
+            ("ResumeThread", [wintypes.HANDLE], wintypes.DWORD),
+            ("WaitForSingleObject", [wintypes.HANDLE, wintypes.DWORD], wintypes.DWORD),
+        ]:
+            function = getattr(self.api, name)
+            function.argtypes, function.restype = args, result
+        handle = self.api.CreateJobObjectW(None, None)
+        if not handle:
+            raise ctypes.WinError(ctypes.get_last_error())
+        try:
+            limits = Limits()
+            limits.Basic.Flags = 0x2000  # JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE
+            if not self.api.SetInformationJobObject(handle, 9, ctypes.byref(limits), ctypes.sizeof(limits)):
+                raise ctypes.WinError(ctypes.get_last_error())
+            process_handle = self.api.OpenProcess(0x100 | 0x1, False, process.pid)
+            if not process_handle:
+                raise ctypes.WinError(ctypes.get_last_error())
+            try:
+                if not self.api.AssignProcessToJobObject(handle, process_handle):
+                    raise ctypes.WinError(ctypes.get_last_error())
+            finally:
+                self.api.CloseHandle(process_handle)
+            self.handle = handle
+        except BaseException:
+            self.api.CloseHandle(handle)
+            raise
+
+    def resume(self):
+        from ctypes import wintypes
+        ctypes = self.ctypes
+        class ThreadEntry(ctypes.Structure):
+            _fields_ = [("Size", wintypes.DWORD), ("Usage", wintypes.DWORD), ("Id", wintypes.DWORD),
+                        ("Owner", wintypes.DWORD), ("BasePriority", wintypes.LONG),
+                        ("DeltaPriority", wintypes.LONG), ("Flags", wintypes.DWORD)]
+        snapshot = self.api.CreateToolhelp32Snapshot(0x4, 0)  # TH32CS_SNAPTHREAD
+        if snapshot == ctypes.c_void_p(-1).value:
+            raise ctypes.WinError(ctypes.get_last_error())
+        try:
+            entry = ThreadEntry()
+            entry.Size = ctypes.sizeof(entry)
+            found = self.api.Thread32First(snapshot, ctypes.byref(entry))
+            while found:
+                if entry.Owner == self.process.pid:
+                    thread = self.api.OpenThread(0x2, False, entry.Id)
+                    if not thread: raise ctypes.WinError(ctypes.get_last_error())
+                    try:
+                        if self.api.ResumeThread(thread) == 0xffffffff:
+                            raise ctypes.WinError(ctypes.get_last_error())
+                        return
+                    finally:
+                        self.api.CloseHandle(thread)
+                found = self.api.Thread32Next(snapshot, ctypes.byref(entry))
+            raise RuntimeError("Не найден поток запуска помощника.")
+        finally:
+            self.api.CloseHandle(snapshot)
+
+    def terminate(self):
+        with self.lock:
+            if os.name == "nt":
+                if not self.handle:
+                    return
+                from ctypes import wintypes
+                capacity = 16
+                while True:
+                    class ProcessIds(self.ctypes.Structure):
+                        _fields_ = [("Assigned", wintypes.DWORD), ("Count", wintypes.DWORD), ("Ids", self.ctypes.c_size_t * capacity)]
+                    members = ProcessIds()
+                    if self.api.QueryInformationJobObject(self.handle, 3, self.ctypes.byref(members), self.ctypes.sizeof(members), None):
+                        break
+                    if self.ctypes.get_last_error() != 234:  # ERROR_MORE_DATA
+                        raise self.ctypes.WinError(self.ctypes.get_last_error())
+                    capacity = max(capacity * 2, members.Assigned)
+                handles = []
+                deadline = time.monotonic() + 10
+                try:
+                    for pid in members.Ids[:members.Count]:
+                        handle = self.api.OpenProcess(0x100000, False, pid)  # SYNCHRONIZE
+                        if handle: handles.append(handle)
+                    if not self.api.TerminateJobObject(self.handle, 1):
+                        raise self.ctypes.WinError(self.ctypes.get_last_error())
+                    # Job accounting can reach zero before individual process
+                    # handles signal. Wait for FFmpeg to release its files too.
+                    for handle in handles:
+                        timeout = max(0, int((deadline - time.monotonic()) * 1000))
+                        result = self.api.WaitForSingleObject(handle, timeout)
+                        if result == 258: raise TimeoutError("Не удалось дождаться остановки процессов загрузки.")
+                        if result != 0: raise self.ctypes.WinError(self.ctypes.get_last_error())
+                finally:
+                    for handle in handles: self.api.CloseHandle(handle)
+            else:
+                import signal
+                try:
+                    os.killpg(self.process.pid, signal.SIGKILL)
+                except ProcessLookupError:
+                    pass
+        self.process.wait(timeout=10)
+
+    def close(self):
+        self.terminate()
+        with self.lock:
+            if self.handle:
+                self.api.CloseHandle(self.handle)
+                self.handle = None

host/protocol.py

@@ -0,0 +1,40 @@
+import json
+import struct
+
+MAX_MESSAGE = 1024 * 1024
+
+
+def read_exact(stream, length):
+    data = bytearray()
+    while len(data) < length:
+        chunk = stream.read(length - len(data))
+        if not chunk:
+            if not data:
+                return None
+            raise EOFError("Оборвано сообщение native messaging.")
+        data.extend(chunk)
+    return bytes(data)
+
+
+def read_message(stream):
+    header = read_exact(stream, 4)
+    if header is None:
+        return None
+    size = struct.unpack("<I", header)[0]
+    if not 0 < size <= MAX_MESSAGE:
+        raise ValueError("Превышен размер сообщения.")
+    raw = read_exact(stream, size)
+    if raw is None:
+        raise EOFError("Отсутствует тело сообщения.")
+    message = json.loads(raw.decode("utf-8"))
+    if not isinstance(message, dict):
+        raise ValueError("Сообщение должно быть объектом.")
+    return message
+
+
+def write_message(stream, message):
+    raw = json.dumps(message, ensure_ascii=False, allow_nan=False, separators=(",", ":")).encode("utf-8")
+    if len(raw) > MAX_MESSAGE:
+        raise ValueError("Ответ слишком большой.")
+    stream.write(struct.pack("<I", len(raw)) + raw)
+    stream.flush()

host/session.py

@@ -0,0 +1,60 @@
+"""Validate YouTube-only cookies and attach them to an in-memory yt-dlp jar."""
+from __future__ import annotations
+import math
+import re
+from http.cookiejar import Cookie
+
+DOMAIN = re.compile(r"^(?:[a-z0-9-]+\.)*youtube\.com$", re.I)
+NAME = re.compile(r"^[!#$%&'*+.^_`|~0-9A-Za-z-]{1,256}$")
+
+
+def validate_cookies(value):
+    if value is None:
+        return []
+    if not isinstance(value, list) or len(value) > 300:
+        raise ValueError("Некорректные данные входа YouTube.")
+    result, size = [], 0
+    for entry in value:
+        if not isinstance(entry, dict):
+            raise ValueError("Некорректные данные входа YouTube.")
+        name, content, domain, path = (entry.get(key) for key in ("name", "value", "domain", "path"))
+        if not isinstance(domain, str) or len(domain) > 253 or not DOMAIN.fullmatch(domain.lstrip(".")) or domain.startswith(".."):
+            raise ValueError("Данные входа разрешены только для YouTube.")
+        if (not isinstance(name, str) or not NAME.fullmatch(name) or not isinstance(content, str) or len(content) > 16384
+                or any(char in content for char in "\r\n\x00") or not isinstance(path, str) or not path.startswith("/")
+                or len(path) > 2048 or any(char in path for char in "\r\n\x00")):
+            raise ValueError("Некорректные данные входа YouTube.")
+        expires = entry.get("expirationDate")
+        if expires is not None and (isinstance(expires, bool) or not isinstance(expires, (int, float)) or not math.isfinite(expires) or not 0 <= expires < 2**63):
+            raise ValueError("Некорректный срок действия входа YouTube.")
+        size += len((name + content + domain + path).encode("utf-8"))
+        if size > 512 * 1024:
+            raise ValueError("Превышен размер данных входа YouTube.")
+        result.append({"name": name, "value": content, "domain": domain.lower(), "path": path,
+                       "secure": bool(entry.get("secure", True)), "httpOnly": bool(entry.get("httpOnly")),
+                       "hostOnly": bool(entry.get("hostOnly", not domain.startswith("."))), "expirationDate": expires})
+    return result
+
+
+def apply_cookies(ydl, cookies):
+    for entry in validate_cookies(cookies):
+        expires = entry["expirationDate"]
+        ydl.cookiejar.set_cookie(Cookie(
+            version=0, name=entry["name"], value=entry["value"], port=None, port_specified=False,
+            domain=entry["domain"], domain_specified=not entry["hostOnly"], domain_initial_dot=entry["domain"].startswith("."),
+            path=entry["path"], path_specified=True, secure=entry["secure"],
+            expires=int(expires) if expires is not None else None, discard=expires is None,
+            comment=None, comment_url=None, rest={"HttpOnly": None} if entry["httpOnly"] else {}, rfc2109=False))
+
+
+def is_access_error(error):
+    return bool(re.search(r"sign in to confirm|not a bot|cookies.*authentication|login required|log in to|HTTP Error (?:403|410)", str(error), re.I))
+
+
+def public_error(error, authenticated=False):
+    message = str(error)
+    if re.search(r"sign in to confirm|not a bot|cookies.*authentication|login required|log in to", message, re.I):
+        if authenticated:
+            return "YouTube отклонил вход браузера или просит проверку. Откройте этот ролик на YouTube, пройдите проверку, затем нажмите «Проверить вход» и повторите загрузку."
+        return "YouTube отклонил запрос загрузчика и просит проверку на бота. Повторите запрос или обновите yt-dlp в компонентах. Дополнительно можно подключить вход кнопкой «Использовать вход в YouTube». Помощник работает; переустановка не нужна."
+    return message[:2000]

host/updates.py

@@ -0,0 +1,289 @@
+"""Verified vendor downloads, staged runtimes and publication through the manager."""
+from __future__ import annotations
+import concurrent.futures
+import hashlib
+import importlib.metadata
+import json
+import os
+import re
+import shutil
+import subprocess
+import sys
+import time
+import threading
+import uuid
+import zipfile
+from pathlib import Path
+from urllib.parse import urlsplit
+
+import requests
+from host.bundle import ROOT, installation_root, manifest
+from host.media import NO_WINDOW, run_small
+
+ALLOWED_HOSTS = {"www.python.org", "nodejs.org", "api.github.com", "github.com", "release-assets.githubusercontent.com", "objects.githubusercontent.com", "pypi.org", "files.pythonhosted.org"}
+FFMPEG_ASSET = "ffmpeg-master-latest-win64-gpl-shared.zip"
+SETTINGS_LOCK = threading.Lock()
+
+
+def settings(enabled=None, **changes):
+    with SETTINGS_LOCK:
+        return _settings(enabled, **changes)
+
+
+def _settings(enabled=None, **changes):
+    installed = installation_root()
+    if not installed:
+        return {"enabled": False, "supported": False}
+    path = installed / "data/update-settings.json"
+    try: value = json.loads(path.read_text(encoding="utf-8"))
+    except (OSError, ValueError): value = {}
+    value = {"enabled": value.get("enabled", True) is True, "lastCheck": value.get("lastCheck", 0), **value}
+    if enabled is not None or changes:
+        if enabled is not None: value["enabled"] = enabled is True
+        value.update(changes)
+        path.parent.mkdir(parents=True, exist_ok=True)
+        temporary = path.with_name(path.name + "." + uuid.uuid4().hex + ".tmp")
+        temporary.write_text(json.dumps(value, ensure_ascii=False), encoding="utf-8")
+        temporary.replace(path)
+    return value
+
+
+def due():
+    value = settings()
+    return value["enabled"] and time.time() - value.get("lastCheck", 0) >= 86400
+
+
+def trusted_url(url):
+    parsed = urlsplit(url)
+    if parsed.scheme != "https" or parsed.hostname not in ALLOWED_HOSTS or parsed.username or parsed.password or parsed.port not in {None, 443}:
+        raise ValueError("Неизвестный источник обновления.")
+    return url
+
+
+def get(url, **kwargs):
+    trusted_url(url)
+    try:
+        headers = {"User-Agent": "YouTubeDL/1.3"}
+        if urlsplit(url).hostname == "api.github.com": headers["Accept"] = "application/vnd.github+json"
+        response = requests.get(url, headers=headers, timeout=(15, 40), **kwargs)
+        for item in [*response.history, response]: trusted_url(item.url)
+        response.raise_for_status()
+        return response
+    except requests.RequestException as error:
+        raise ValueError(f"Не удалось связаться с {urlsplit(url).hostname}. Проверьте подключение и повторите обновление.") from error
+
+
+def digest(path):
+    result = hashlib.sha256()
+    with path.open("rb") as stream:
+        for chunk in iter(lambda: stream.read(1024 * 1024), b""): result.update(chunk)
+    return result.hexdigest()
+
+
+def fetch(item, target, progress):
+    expected = item.get("sha256", "")
+    if not re.fullmatch("[a-f0-9]{64}", expected): raise ValueError("Источник не предоставил SHA256 обновления.")
+    with get(item["url"], stream=True) as response, target.open("wb") as output:
+        total = int(response.headers.get("Content-Length", 0)); received = 0
+        for chunk in response.iter_content(512 * 1024):
+            output.write(chunk); received += len(chunk)
+            if received > 512 * 1024 * 1024: raise ValueError("Превышен размер компонента.")
+            progress(received / total if total else None)
+    if digest(target) != expected: raise ValueError("Контрольная сумма обновления не совпала. Прежний комплект сохранён.")
+
+
+def safe_members(package):
+    if sum(item.file_size for item in package.infolist()) > 1024 * 1024 * 1024:
+        raise ValueError("Превышен размер распакованного компонента.")
+    for item in package.infolist():
+        name = item.filename.replace("\\", "/")
+        parts = name.split("/")
+        if name.startswith("/") or any(part in {"..", "."} or ":" in part for part in parts) or (item.external_attr >> 16) & 0xF000 == 0xA000:
+            raise ValueError("Недопустимый путь в обновлении.")
+        if not item.is_dir(): yield item
+
+
+def extract_zip(archive, target):
+    root = target.resolve()
+    with zipfile.ZipFile(archive) as package:
+        for item in safe_members(package):
+            destination = (root / item.filename).resolve()
+            if root not in destination.parents: raise ValueError("Путь вне папки компонента.")
+            destination.parent.mkdir(parents=True, exist_ok=True)
+            with package.open(item) as source, destination.open("wb") as output: shutil.copyfileobj(source, output)
+
+
+def version_tuple(value):
+    return tuple(int(part) for part in value.lstrip("v").split(".")) if re.fullmatch(r"v?\d+(?:\.\d+)*", value) else ()
+
+
+def python_release():
+    branch = f"{sys.version_info.major}.{sys.version_info.minor}"
+    current = version_tuple(sys.version.split()[0])
+    index = get("https://www.python.org/ftp/python/").text
+    versions = sorted(set(re.findall(r'href="(' + re.escape(branch) + r'\.\d+)/"', index)), key=version_tuple, reverse=True)
+    for version in versions:
+        if version_tuple(version) <= current: break
+        page = get(f"https://www.python.org/downloads/release/python-{version.replace('.', '')}/").text
+        name = f"python-{version}-embed-amd64.zip"
+        for row in re.findall(r"<tr\b[^>]*>(.*?)</tr>", page, re.S):
+            if name not in row: continue
+            match = re.search(r"\b[a-f0-9]{64}\b", re.sub(r"<[^>]+>", " ", row))
+            if match:
+                return {"id": "python", "version": version, "url": f"https://www.python.org/ftp/python/{version}/{name}", "sha256": match[0]}
+    return None
+
+
+def node_release():
+    current = run_small([str(ROOT / "runtime/bin/node.exe"), "--version"]).stdout.strip()
+    releases = get("https://nodejs.org/dist/index.json").json()
+    compatible = [item for item in releases if item.get("lts") and "win-x64-zip" in item.get("files", [])
+                  and version_tuple(item["version"])[:1] == version_tuple(current)[:1] and version_tuple(item["version"]) > version_tuple(current)]
+    if not compatible: return None
+    version = max(compatible, key=lambda item: version_tuple(item["version"]))["version"]
+    name = f"node-{version}-win-x64.zip"
+    checksum = next((line.split()[0] for line in get(f"https://nodejs.org/dist/{version}/SHASUMS256.txt").text.splitlines() if line.split() and line.split()[-1] == name), None)
+    return {"id": "node", "version": version, "url": f"https://nodejs.org/dist/{version}/{name}", "sha256": checksum}
+
+
+def ffmpeg_release():
+    release = get("https://api.github.com/repos/yt-dlp/FFmpeg-Builds/releases/latest").json()
+    asset = next(item for item in release["assets"] if item["name"] == FFMPEG_ASSET)
+    checksum = asset.get("digest", "").removeprefix("sha256:")
+    if not re.fullmatch("[a-f0-9]{64}", checksum): raise ValueError("FFmpeg не предоставил SHA256. Обновление отложено.")
+    previous = next((item.get("sha256") for item in manifest()["sources"] if FFMPEG_ASSET in item["url"]), None)
+    if previous == checksum: return None
+    return {"id": "ffmpeg", "version": asset["updated_at"], "url": asset["browser_download_url"], "sha256": checksum}
+
+
+def packages_release():
+    installed = {item.metadata["Name"]: item.version for item in importlib.metadata.distributions(path=[str(ROOT / "runtime/python/Lib/site-packages")])}
+    def newer(item):
+        name, version = item
+        release = get(f"https://pypi.org/pypi/{name}/json").json()["info"]["version"]
+        return version_tuple(release) > version_tuple(version)
+    with concurrent.futures.ThreadPoolExecutor(max_workers=6) as executor:
+        changed = any(list(executor.map(newer, installed.items())))
+    return {"id": "packages", "version": "latest-compatible"} if changed else None
+
+
+def check_updates():
+    if not installation_root(): raise ValueError("Для обновления установите автономный помощник.")
+    with concurrent.futures.ThreadPoolExecutor(max_workers=4) as executor:
+        candidates = list(executor.map(lambda task: task(), [python_release, node_release, ffmpeg_release, packages_release]))
+    return [item for item in candidates if item]
+
+
+def resolve_packages(stage, work, progress):
+    progress(None, "Подбираю совместимые версии Python-пакетов…")
+    release = get("https://pypi.org/pypi/pip/json").json()
+    wheel = next(item for item in release["urls"] if item["filename"].endswith("-py3-none-any.whl") and not item.get("yanked"))
+    pip = work / "pip.whl"
+    fetch({"url": wheel["url"], "sha256": wheel["digests"]["sha256"]}, pip, lambda _: None)
+    report = work / "python-packages.json"
+    script = "import sys;sys.path.insert(0,sys.argv.pop(1));from pip._internal.cli.main import main;raise SystemExit(main(sys.argv[1:]))"
+    command = [str(stage / "runtime/python/python.exe"), "-I", "-X", "utf8", "-B", "-c", script, str(pip), "--isolated", "--disable-pip-version-check", "install",
+               "--dry-run", "--ignore-installed", "--only-binary=:all:", "--no-cache-dir", "--quiet", "--report", str(report), "--index-url", "https://pypi.org/simple", "yt-dlp[default]", "yt-dlp-ejs"]
+    result = subprocess.run(command, capture_output=True, text=True, encoding="utf-8", errors="replace", timeout=600, creationflags=NO_WINDOW,
+                            env={**os.environ, "TEMP": str(work), "TMP": str(work)}, stdin=subprocess.DEVNULL)
+    if result.returncode: raise ValueError("Не удалось подобрать совместимые Python-пакеты. " + result.stderr[-1200:])
+    records = json.loads(report.read_text(encoding="utf-8"))["install"]
+    packages = stage / "runtime/python/Lib/site-packages"
+    if packages.exists(): shutil.rmtree(packages)
+    packages.mkdir(parents=True)
+    for index, record in enumerate(records):
+        info = record["download_info"]; name = record["metadata"]["name"]
+        archive = work / f"wheel-{index}.whl"
+        fetch({"url": info["url"], "sha256": info["archive_info"]["hashes"]["sha256"]}, archive,
+              lambda fraction: progress(None, f"Скачиваю {name}…"))
+        with zipfile.ZipFile(archive) as wheel:
+            for member in safe_members(wheel):
+                relative = member.filename.split("/")
+                if relative[0].endswith(".data"):
+                    if len(relative) < 3 or relative[1] not in {"purelib", "platlib"}: continue
+                    relative = relative[2:]
+                destination = packages.joinpath(*relative).resolve()
+                if packages.resolve() not in destination.parents: raise ValueError("Некорректный путь Python-пакета.")
+                destination.parent.mkdir(parents=True, exist_ok=True)
+                destination.write_bytes(wheel.read(member))
+    return {item["metadata"]["name"]: item["metadata"]["version"] for item in records}
+
+
+def publish(stage):
+    installed = installation_root()
+    manager = installed / "YouTubeDL-Manager.exe"
+    result = run_small([str(manager), "--activate-release", str(stage), "--expected-current", str(ROOT), "--target-root", str(installed), "--silent"], timeout=180)
+    if result.returncode: raise ValueError("Новый комплект не прошёл проверку. Прежняя версия сохранена. " + result.stderr[-1000:])
+
+
+def update(progress, workspace, candidates=None):
+    installed = installation_root()
+    if not installed: raise ValueError("Обновление доступно в автономном комплекте.")
+    progress(None, "Проверяю новые версии компонентов…")
+    candidates = check_updates() if candidates is None else candidates
+    settings(lastCheck=time.time())
+    if not candidates: return {"title": "Все компоненты актуальны", "changed": False}
+    releases = installed / "releases"
+    stage = releases / (".ytdl-update-" + uuid.uuid4().hex)
+    if stage.resolve().parent != releases.resolve() or releases.is_symlink(): raise ValueError("Недопустимая папка обновления.")
+    if shutil.disk_usage(releases).free < 1024 ** 3: raise ValueError("Для обновления нужен 1 ГБ свободного места.")
+    stage.mkdir(); workspace(str(stage))
+    published = False
+    try:
+        progress(5, "Готовлю новую версию комплекта…")
+        owned = json.loads((ROOT / "bundle-files.json").read_text(encoding="utf-8"))
+        for relative in owned:
+            source, target = (ROOT / relative).resolve(), (stage / relative).resolve()
+            if ROOT not in source.parents or stage.resolve() not in target.parents or source.is_symlink():
+                raise ValueError("Некорректный файл установленного комплекта.")
+            target.parent.mkdir(parents=True, exist_ok=True)
+            shutil.copyfile(source, target)
+        work = stage / ".update-work"; work.mkdir()
+        metadata = json.loads((stage / "bundle.json").read_text(encoding="utf-8"))
+        for index, item in enumerate(candidates):
+            if item["id"] == "packages":
+                metadata["pythonPackages"] = resolve_packages(stage, work, progress)
+                continue
+            archive = work / f"{item['id']}.zip"
+            label = {"python": "Python", "node": "Node.js", "ffmpeg": "FFmpeg"}[item["id"]]
+            fetch(item, archive, lambda fraction: progress(10 + (index + (fraction or 0)) / len(candidates) * 60 if fraction is not None else None, f"Скачиваю {label} {item['version']}…"))
+            if item["id"] == "python":
+                python = stage / "runtime/python"
+                saved = work / "site-packages"
+                shutil.copytree(python / "Lib/site-packages", saved)
+                shutil.rmtree(python); python.mkdir()
+                extract_zip(archive, python)
+                shutil.copytree(saved, python / "Lib/site-packages")
+                pth = next(python.glob("python*._pth"))
+                pth.write_text(f"{pth.stem}.zip\n.\nLib/site-packages\n../../\nimport site\n", encoding="ascii")
+            else:
+                with zipfile.ZipFile(archive) as package:
+                    for member in safe_members(package):
+                        name = Path(member.filename).name
+                        binary = name == "node.exe" if item["id"] == "node" else "/bin/" in member.filename and (name in {"ffmpeg.exe", "ffprobe.exe"} or name.endswith(".dll"))
+                        if binary: (stage / "runtime/bin" / name).write_bytes(package.read(member))
+                        elif name in {"LICENSE", "LICENSE.txt"}: (stage / "licenses" / f"{label}-LICENSE.txt").write_bytes(package.read(member))
+            source = {"url": item["url"], "file": Path(urlsplit(item["url"]).path).name, "sha256": item["sha256"]}
+            metadata["sources"] = [old for old in metadata["sources"] if not (item["id"] == "python" and "python.org" in old["url"] or item["id"] == "node" and "nodejs.org" in old["url"] or item["id"] == "ffmpeg" and FFMPEG_ASSET in old["url"])] + [source]
+        shutil.rmtree(work)
+        for item in candidates:
+            if item["id"] in {"python", "node"}:
+                executable = stage / ("runtime/python/python.exe" if item["id"] == "python" else "runtime/bin/node.exe")
+                actual = run_small([str(executable), "--version"]).stdout.strip().removeprefix("Python ")
+                if actual != item["version"]: raise ValueError("Версия скачанного компонента не совпала с релизом.")
+        third_party = stage / "licenses/THIRD-PARTY.txt"
+        if third_party.exists():
+            third_party.write_text(re.sub(r"yt-dlp source:.*", "yt-dlp source: https://github.com/yt-dlp/yt-dlp (installed version in Python metadata)", third_party.read_text(encoding="utf-8")), encoding="utf-8")
+        metadata["updatedAt"] = time.time()
+        (stage / "bundle.json").write_text(json.dumps(metadata, indent=2), encoding="utf-8")
+        records = {str(path.relative_to(stage)).replace("\\", "/"): digest(path) for path in stage.rglob("*") if path.is_file() and path.name != "bundle-files.json"}
+        (stage / "bundle-files.json").write_text(json.dumps(records, indent=2), encoding="utf-8")
+        progress(85, "Проверяю новый комплект и подключаю помощник…")
+        publish(stage); published = True
+        settings(lastUpdate=time.time())
+        return {"title": "Компоненты обновлены", "changed": True, "restartRequired": True, "components": [item["id"] for item in candidates]}
+    finally:
+        # Only our generated, unpublished staging directory can be removed.
+        if not published and stage.exists() and stage.resolve().parent == releases.resolve() and not stage.is_symlink():
+            marker = json.loads((installed / "installation.json").read_text(encoding="utf-8-sig"))
+            if Path(marker["current"]).resolve() != stage.resolve(): shutil.rmtree(stage)

host/worker.py

@@ -0,0 +1,293 @@
+"""Isolated, cancellable download worker. Stdout contains JSON lines only."""
+from __future__ import annotations
+
+import json
+import errno
+import os
+import subprocess
+import sys
+import tempfile
+import threading
+import time
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from host.common import safe_filename, select_streams, summarize, validate_download, youtube_url
+from host.media import NO_WINDOW, config, encoding_plan, ffmpeg_command, probe, tool
+from host.session import apply_cookies, public_error, is_access_error
+from host.ffmpeg_progress import run_ffmpeg
+
+
+def emit(kind, **data):
+    print(json.dumps({"type": kind, **data}, ensure_ascii=False, allow_nan=False), flush=True)
+
+
+class QuietLogger:
+    def debug(self, message):
+        pass
+    def info(self, message):
+        pass
+    def warning(self, message):
+        pass
+    def error(self, message):
+        # The raised DownloadError is reported through the structured channel.
+        pass
+
+
+def ydl_options():
+    try:
+        node = tool("node")
+    except ValueError:
+        node = None
+    options = {"quiet": True, "no_warnings": True, "logger": QuietLogger(), "noplaylist": True,
+               "socket_timeout": 20, "retries": 3, "fragment_retries": 5,
+               # Parallel HLS requests can trigger YouTube's fragment throttling;
+               # never skip failed fragments and silently publish an incomplete clip.
+               "concurrent_fragment_downloads": 1, "skip_unavailable_fragments": False,
+               "ffmpeg_location": str(Path(tool("ffmpeg")).parent),
+               "windowsfilenames": True, "cachedir": False, "noprogress": True}
+    if node:
+        options["js_runtimes"] = {"node": {"path": node}}
+    return options
+
+
+def inspect(url, cookies=None):
+    from yt_dlp import YoutubeDL
+    from yt_dlp.utils import DownloadError
+    for attempt in range(2):
+        try:
+            with YoutubeDL(ydl_options()) as ydl:
+                apply_cookies(ydl, cookies)
+                return summarize(ydl.extract_info(youtube_url(url), download=False))
+        except DownloadError as error:
+            if attempt or not is_access_error(error):
+                raise
+            time.sleep(1.5)
+
+
+def convert(source, target, options, media, encoders):
+    plan = encoding_plan(options, media, encoders)
+    duration = float(media.get("format", {}).get("duration") or 0)
+    attempts = [(plan, True)]
+    if plan["engine"] in {"nvenc", "amf"}:
+        attempts.append((plan, False))
+        if options["engine"] == "auto":
+            attempts.append(({**plan, "engine": "cpu"}, False))
+    last_error = ""
+    for index, (attempt, cuda_decode) in enumerate(attempts):
+        stage = "encoding" if attempt["video"] not in (None, "copy") else ("audio" if attempt["audio"] not in (None, "copy") else "remuxing")
+        emit("progress", stage=stage, percent=0, engine=attempt["engine"], codec=attempt["video"] or attempt["audio"],
+             message="", speed="", eta=None)
+        command = ffmpeg_command(source, target, options, attempt, cuda_decode)
+        returncode, errors = run_ffmpeg(command, duration, stage, attempt["engine"], lambda **data: emit("progress", **data))
+        if returncode == 0 and target.is_file() and target.stat().st_size:
+            # Verify the result really has the requested streams before publishing it.
+            output = probe(target)
+            types = {s.get("codec_type") for s in output.get("streams", [])}
+            required = {"audio"} if options["mode"] == "audio" else ({"video", "audio"} if options["mode"] == "video" else {"video"})
+            if not required <= types or (options["mode"] == "video_only" and "audio" in types):
+                raise ValueError("Проверка итогового файла не прошла: отсутствует выбранная дорожка.")
+            return attempt
+        last_error = errors.strip()[-1600:]
+        if index + 1 < len(attempts):
+            next_plan, next_decode = attempts[index + 1]
+            emit("progress", stage="encoding", percent=0, engine=attempt["engine"],
+                 message="Повтор с обычным декодированием" if next_plan["engine"] == attempt["engine"] else "Аппаратное кодирование недоступно: переход на CPU", speed="", eta=None)
+    raise ValueError("FFmpeg не смог обработать видео. " + last_error)
+
+
+def publish_file(source: Path, folder: Path, name: str, extension: str) -> Path:
+    if source.stat().st_dev != folder.stat().st_dev:
+        # Copy to an unpublished file on the destination disk, then publish it
+        # atomically. Cancellation cannot leave a partial final filename.
+        with tempfile.TemporaryDirectory(prefix=".ytdl-", dir=folder) as staging:
+            staging_path = Path(staging).resolve()
+            emit("workspace", path=str(staging_path), purpose="saving")
+            target = staging_path / ("ready." + extension)
+            total, copied, last_emit = source.stat().st_size, 0, 0.0
+            emit("progress", stage="saving", percent=0, copied=0, total=total, speed=None, eta=None)
+            with source.open("rb") as incoming, target.open("xb") as outgoing:
+                while chunk := incoming.read(4 * 1024 * 1024):
+                    outgoing.write(chunk)
+                    copied += len(chunk)
+                    if time.monotonic() - last_emit >= 0.2:
+                        last_emit = time.monotonic()
+                        emit("progress", stage="saving", percent=min(99, copied / total * 100) if total else 0,
+                             copied=copied, total=total, speed=None, eta=None)
+                outgoing.flush()
+                os.fsync(outgoing.fileno())
+            destination = publish_file(target, folder, name, extension)
+            source.unlink()
+            return destination
+    # Same-volume hard-link creation is atomic and never overwrites an existing file.
+    for index in range(10000):
+        suffix = "" if index == 0 else f" ({index})"
+        destination = folder / f"{name}{suffix}.{extension}"
+        if destination.exists():
+            continue
+        try:
+            os.link(source, destination)
+            source.unlink()
+            return destination
+        except FileExistsError:
+            continue
+        except OSError as error:
+            if destination.exists():
+                continue
+            if error.errno == errno.EXDEV or getattr(error, "winerror", None) == 17:
+                raise ValueError("Не удалось сохранить файл на выбранный диск.") from error
+            # Windows rename also refuses to replace existing destinations, including on FAT/exFAT.
+            if os.name != "nt":
+                raise
+            try:
+                os.rename(source, destination)
+                return destination
+            except FileExistsError:
+                continue
+            except OSError:
+                if destination.exists():
+                    continue
+                raise
+    raise ValueError("Не удалось выбрать свободное имя файла.")
+
+
+def download(payload, encoders):
+    from yt_dlp import YoutubeDL
+    from yt_dlp.postprocessor.ffmpeg import FFmpegMergerPP, FFmpegPostProcessorError
+    from yt_dlp.utils import DownloadError
+    options = validate_download(payload)
+    emit("progress", stage="preparing", percent=None, message="Получаю свежие ссылки на дорожки")
+    folder = Path(options["folder"])
+    work_folder = Path(options["workFolder"])
+    # Only this job's generated directory is removed on exit; final files live outside it.
+    # A failed downloader can retain an open .part handle until this worker exits.
+    # Preserve its actual error; the native host cleans up again after process exit.
+    with tempfile.TemporaryDirectory(prefix=".ytdl-", dir=work_folder, ignore_cleanup_errors=True) as scratch:
+        scratch_path = Path(scratch).resolve()
+        if scratch_path.parent != work_folder.resolve():
+            raise ValueError("Некорректная временная папка.")
+        emit("workspace", path=str(scratch_path))
+        last_emit = 0.0
+        finished_tracks = set()
+        track_count = 1
+        def format_selector(context):
+            nonlocal track_count
+            selector = select_streams(context, options)
+            track_count = 2 if "+" in selector else 1
+            # Keep extraction and downloading in the same YoutubeDL instance so
+            # its visitor cookies and request state remain available.
+            return ydl.build_format_selector(selector)(context)
+        def reject_live(info, *, incomplete=False):
+            if info.get("is_live"):
+                return "Дождитесь окончания прямой трансляции."
+        def progress(event):
+            nonlocal last_emit
+            if event.get("status") == "finished":
+                finished_tracks.add(event.get("filename", ""))
+                return
+            if event.get("status") != "downloading" or time.monotonic() - last_emit < 0.2:
+                return
+            last_emit = time.monotonic()
+            downloaded = event.get("downloaded_bytes", 0)
+            total = event.get("total_bytes") or event.get("total_bytes_estimate") or 0
+            track_progress = min(1, downloaded / total) if total else 0
+            percent = min(99, (len(finished_tracks) + track_progress) / track_count * 100) if total else None
+            stream = event.get("info_dict", {})
+            track = "audio" if stream.get("vcodec") == "none" else "video"
+            emit("progress", stage="downloading", track=track, percent=percent,
+                 downloaded=downloaded, total=total, speed=event.get("speed"), eta=event.get("eta"))
+        def postprocess(event):
+            if event.get("status") == "started" and event.get("postprocessor") == "Merger":
+                emit("progress", stage="merging", percent=0, engine="copy", speed="", eta=None,
+                     processedSeconds=0, durationSeconds=0, written=0, message="Подготовка дорожек к объединению")
+
+        class ProgressMerger(FFmpegMergerPP):
+            def run(self, info):
+                self.duration = info.get("duration") or 0
+                return super().run(info)
+
+            def run_ffmpeg_multiple_files(self, inputs, output, opts, **kwargs):
+                self.check_version()
+                oldest_mtime = min(os.stat(path).st_mtime for path in inputs)
+                command = [self.executable, "-hide_banner", "-nostdin", "-loglevel", "info", "-y",
+                           "-progress", "pipe:1", "-stats_period", "0.4"]
+                for path in inputs:
+                    command += ["-i", str(path)]
+                # Preserve yt-dlp's maps and AAC fixup, including HLS audio.
+                command += list(opts) + [str(output)]
+                code, errors = run_ffmpeg(command, self.duration, "merging", "copy", lambda **data: emit("progress", **data))
+                if code:
+                    raise FFmpegPostProcessorError(errors.strip()[-1600:] or "Не удалось объединить дорожки.")
+                self.try_utime(output, oldest_mtime, oldest_mtime)
+
+        def enable_merge_progress(ydl):
+            original_run_pp = ydl.run_pp
+            def run_pp(pp, info):
+                if isinstance(pp, FFmpegMergerPP) and not isinstance(pp, ProgressMerger):
+                    pp = ProgressMerger(ydl)
+                return original_run_pp(pp, info)
+            ydl.run_pp = run_pp
+        download_options = {**ydl_options(), "format": format_selector, "match_filter": reject_live,
+                            "outtmpl": str(scratch_path / "source.%(ext)s"),
+                            "merge_output_format": "mkv", "progress_hooks": [progress],
+                            "postprocessor_hooks": [postprocess], "overwrites": False}
+        for attempt in range(2):
+            try:
+                with YoutubeDL(download_options) as ydl:
+                    enable_merge_progress(ydl)
+                    apply_cookies(ydl, payload.get("browserCookies"))
+                    downloaded_info = ydl.extract_info(options["url"], download=True)
+                break
+            except DownloadError as error:
+                if attempt == 0 and (is_access_error(error) or "403" in str(error) or "410" in str(error)):
+                    finished_tracks.clear()
+                    emit("progress", stage="preparing", percent=None, message="Обновляю ссылки YouTube и повторяю загрузку")
+                    time.sleep(1.5)
+                else:
+                    raise
+        if not downloaded_info:
+            raise ValueError("Ролик недоступен для загрузки.")
+        title = str(downloaded_info.get("title", "Видео"))
+        name = safe_filename(options["filename"] or title, str(downloaded_info.get("id", "video")))
+        candidates = [p for p in scratch_path.glob("source.*") if p.is_file() and p.suffix.lower() in {".mkv", ".mp4", ".webm", ".m4a", ".mp3", ".ogg", ".opus", ".flac", ".wav", ".ts"}]
+        if len(candidates) != 1:
+            raise ValueError("Не удалось определить загруженный медиафайл.")
+        source = candidates[0]
+        media = probe(source)
+        output = scratch_path / f"final.{options['container']}"
+        plan = convert(source, output, options, media, encoders)
+        destination = publish_file(output, folder, name, options["container"])
+    return {"path": str(destination), "filename": destination.name, "title": title,
+            "size": destination.stat().st_size, "engine": plan["engine"],
+            "codec": plan["video"] or plan["audio"], "mode": options["mode"]}
+
+
+def main():
+    task = {}
+    try:
+        task = json.loads(sys.stdin.readline())
+        if task["action"] == "inspect":
+            result = inspect(task["payload"]["url"], task["payload"].get("browserCookies"))
+        elif task["action"] == "download":
+            result = download(task["payload"], task.get("encoders", task.get("nvenc", [])))
+        elif task["action"] == "dependency_install":
+            from host.dependencies import install
+            result = install(task["payload"]["dependency"],
+                             lambda percent, message: emit("progress", stage="installing", percent=percent, message=message),
+                             lambda path: emit("workspace", path=path))
+        elif task["action"] == "helper_update":
+            from host.updates import update
+            result = update(lambda percent, message: emit("progress", stage="updating", percent=percent, message=message),
+                            lambda path: emit("workspace", path=path), task["payload"].get("candidates"))
+        else:
+            raise ValueError("Неизвестная операция.")
+        emit("result", result=result)
+    except Exception as error:
+        emit("error", message=public_error(error, bool(task.get("payload", {}).get("browserCookies"))))
+        return 1
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

install.cmd

@@ -0,0 +1,8 @@
+@echo off
+powershell.exe -NoProfile -ExecutionPolicy Bypass -File "%~dp0install.ps1"
+if errorlevel 1 (
+  echo Installation failed. Read the error above.
+  pause
+  exit /b 1
+)
+pause

install.ps1

@@ -0,0 +1,121 @@
+[CmdletBinding()]
+param(
+    [string]$PythonPath,
+    [string]$FfmpegPath,
+    [string]$NodePath,
+    [switch]$RefreshDependencies,
+    [switch]$SkipRegistration,
+    [switch]$HelperOnly
+)
+$ErrorActionPreference = 'Stop'
+$taskProjectRoot = $PSScriptRoot
+$taskRuntime = Join-Path $taskProjectRoot '.runtime'
+New-Item -ItemType Directory -Path $taskRuntime -Force | Out-Null
+$taskSavedConfig = $null
+if (Test-Path -LiteralPath (Join-Path $taskRuntime 'config.json')) {
+    try { $taskSavedConfig = Get-Content -LiteralPath (Join-Path $taskRuntime 'config.json') -Raw | ConvertFrom-Json } catch {}
+}
+
+function Install-PrivatePython {
+    $taskPythonRoot = Join-Path $taskRuntime 'python'
+    $taskPythonInstaller = Join-Path $taskRuntime 'python-setup.exe'
+    [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
+    Write-Host 'Installing Python from python.org...'
+    Invoke-WebRequest -UseBasicParsing -Uri 'https://www.python.org/ftp/python/3.14.8/python-3.14.8-amd64.exe' -OutFile $taskPythonInstaller
+    $taskSignature = Get-AuthenticodeSignature -LiteralPath $taskPythonInstaller
+    if ($taskSignature.Status -ne 'Valid') { throw 'Python installer signature verification failed.' }
+    $taskArguments = @('/quiet','InstallAllUsers=0',"TargetDir=`"$taskPythonRoot`"",'PrependPath=0','Include_launcher=0','Include_test=0','Include_doc=0','Shortcuts=0','AssociateFiles=0')
+    $taskInstalled = Start-Process -FilePath $taskPythonInstaller -ArgumentList $taskArguments -WindowStyle Hidden -Wait -PassThru
+    if ($taskInstalled.ExitCode -notin @(0,3010)) { throw 'Python installation failed.' }
+    return (Join-Path $taskPythonRoot 'python.exe')
+}
+
+function Find-Tool([string]$ExplicitPath, [string]$Name) {
+    if ($ExplicitPath) {
+        if (-not (Test-Path -LiteralPath $ExplicitPath -PathType Leaf)) { throw "File not found: $ExplicitPath" }
+        return (Resolve-Path -LiteralPath $ExplicitPath).Path
+    }
+    $taskCommand = Get-Command $Name -ErrorAction SilentlyContinue | Select-Object -First 1
+    if ($taskCommand) { return $taskCommand.Source }
+    return $null
+}
+
+if (-not $PythonPath) {
+    $taskExistingPython = Join-Path $env:USERPROFILE '.agent-reach-venv\Scripts\python.exe'
+    $taskProjectPython = Join-Path $taskRuntime 'venv\Scripts\python.exe'
+    if ($taskSavedConfig.python -and (Test-Path -LiteralPath $taskSavedConfig.python)) { $PythonPath = $taskSavedConfig.python }
+    elseif (Test-Path -LiteralPath $taskExistingPython) { $PythonPath = $taskExistingPython }
+    elseif (Test-Path -LiteralPath $taskProjectPython) { $PythonPath = $taskProjectPython }
+    else {
+        $taskSystemPython = Find-Tool '' 'python.exe'
+        if (-not $taskSystemPython -or $taskSystemPython -like '*\WindowsApps\*') { $taskSystemPython = Install-PrivatePython }
+        & $taskSystemPython -c 'import sys; assert sys.version_info >= (3,10)'
+        if ($LASTEXITCODE -ne 0) { $taskSystemPython = Install-PrivatePython }
+        & $taskSystemPython -m venv (Join-Path $taskRuntime 'venv')
+        if ($LASTEXITCODE -ne 0) { throw 'Python virtual environment creation failed.' }
+        $PythonPath = $taskProjectPython
+    }
+}
+$PythonPath = Find-Tool $PythonPath 'python.exe'
+& $PythonPath -c 'import sys; assert sys.version_info >= (3,10), "Python 3.10+ required"'
+if ($LASTEXITCODE -ne 0) { throw 'Unsupported Python version.' }
+& $PythonPath -c 'import yt_dlp, yt_dlp_ejs'
+if ($LASTEXITCODE -ne 0 -or $RefreshDependencies) {
+    & $PythonPath -m pip install --disable-pip-version-check --upgrade -r (Join-Path $taskProjectRoot 'requirements.txt')
+    if ($LASTEXITCODE -ne 0) { throw 'Installing yt-dlp failed.' }
+}
+if (-not $FfmpegPath -and $taskSavedConfig.ffmpeg -and (Test-Path -LiteralPath $taskSavedConfig.ffmpeg)) { $FfmpegPath = $taskSavedConfig.ffmpeg }
+$taskFfmpeg = Find-Tool $FfmpegPath 'ffmpeg.exe'
+$taskFfprobe = if ($taskFfmpeg) { Join-Path (Split-Path -Parent $taskFfmpeg) 'ffprobe.exe' } else { $null }
+if (-not $taskFfprobe -or -not (Test-Path -LiteralPath $taskFfprobe)) { $taskFfprobe = Find-Tool '' 'ffprobe.exe' }
+if (-not $NodePath) {
+    if ($taskSavedConfig.node -and (Test-Path -LiteralPath $taskSavedConfig.node)) { $NodePath = $taskSavedConfig.node }
+    $taskPortableNode = Join-Path $env:USERPROFILE '.agent-reach\tools\node-v24.21.0-win-x64\node.exe'
+    if (-not $NodePath -and (Test-Path -LiteralPath $taskPortableNode)) { $NodePath = $taskPortableNode }
+}
+$taskNode = Find-Tool $NodePath 'node.exe'
+
+$taskUtf8 = [System.Text.UTF8Encoding]::new($false)
+$taskConfig = @{ python=$PythonPath; ffmpeg=$taskFfmpeg; ffprobe=$taskFfprobe; node=$taskNode }
+[System.IO.File]::WriteAllText((Join-Path $taskRuntime 'config.json'), ($taskConfig | ConvertTo-Json), $taskUtf8)
+Push-Location -LiteralPath $taskProjectRoot
+try {
+    if (-not $taskFfmpeg -or -not $taskFfprobe) {
+        & $PythonPath -m host.dependencies ffmpeg
+        if ($LASTEXITCODE -ne 0) { throw 'Installing FFmpeg failed.' }
+    }
+    $taskNodeGood = $false
+    if ($taskNode) {
+        $taskNodeVersion = & $taskNode --version
+        $taskNodeGood = $taskNodeVersion -match '^v(\d+)\.' -and [int]$Matches[1] -ge 22
+    }
+    if (-not $taskNodeGood) {
+        & $PythonPath -m host.dependencies node
+        if ($LASTEXITCODE -ne 0) { throw 'Installing Node.js failed.' }
+    }
+} finally { Pop-Location }
+$taskLauncherPath = Join-Path $taskRuntime 'launch-host.cmd'
+$taskMainPath = Join-Path $taskProjectRoot 'host\main.py'
+$taskLauncher = "@echo off`r`nchcp 65001 >nul`r`nset PYTHONIOENCODING=utf-8`r`nset PYTHONUTF8=1`r`n`"$PythonPath`" -u `"$taskMainPath`" %*`r`n"
+[System.IO.File]::WriteAllText($taskLauncherPath, $taskLauncher, $taskUtf8)
+$taskExtensionId = 'ndnoeiaecgmjnjneekaeapeecmmjheli'
+$taskHostName = 'com.youtubedl.native'
+$taskNativeManifestPath = Join-Path $taskRuntime 'native-host.json'
+$taskNativeManifest = @{ name=$taskHostName; description='YouTubeDL download and NVIDIA NVENC helper'; path=$taskLauncherPath; type='stdio'; allowed_origins=@("chrome-extension://$taskExtensionId/") }
+[System.IO.File]::WriteAllText($taskNativeManifestPath, ($taskNativeManifest | ConvertTo-Json), $taskUtf8)
+if (-not $SkipRegistration) {
+    foreach ($taskBrowser in @('Google\Chrome','Microsoft\Edge','Chromium')) {
+        $taskRegistryPath = "HKCU:\Software\$taskBrowser\NativeMessagingHosts\$taskHostName"
+        New-Item -Path $taskRegistryPath -Force | Out-Null
+        Set-Item -Path $taskRegistryPath -Value $taskNativeManifestPath
+    }
+}
+Write-Host $(if ($SkipRegistration) { 'Native helper files prepared.' } else { 'Native helper registered for Edge and Chrome (current user).' })
+Write-Host "Extension ID: $taskExtensionId"
+if ($HelperOnly) {
+    Write-Host 'Return to YouTubeDL settings and press Start.'
+} else {
+    Write-Host "Extension folder: $(Join-Path $taskProjectRoot 'extension')"
+    Write-Host 'Open edge://extensions or chrome://extensions, enable Developer mode, and load the extension folder.'
+    Write-Host 'Then refresh the YouTube page. The Download and Settings buttons are next to Subscribe.'
+}

package-lock.json

@@ -0,0 +1,43 @@
+{
+  "name": "youtubedl",
+  "version": "1.4.5",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "youtubedl",
+      "version": "1.4.5",
+      "license": "SEE LICENSE IN LICENSE",
+      "devDependencies": {
+        "playwright": "^1.64.0"
+      }
+    },
+    "node_modules/playwright": {
+      "version": "1.64.0",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.64.0.tgz",
+      "integrity": "sha512-kVzTnYFYEyQ9RGzBjNCd2+yEqWmVbxl3AHPynv3qQ6JTjv4a+kwRcnqQwIpuP3NnrnIrE/Q6wWAIAvMfIE2/Yg==",
+      "dev": true,
+      "dependencies": {
+        "playwright-core": "1.64.0"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/playwright-core": {
+      "version": "1.64.0",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.64.0.tgz",
+      "integrity": "sha512-T9r+MZkTECl2+oUcZ26YgZzTrYidTsIhYYkJix+6iDOymOb1FB2RLLSOxRGnZGv5DStt+aduIVbt+E8WygXYpg==",
+      "dev": true,
+      "bin": {
+        "playwright-core": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    }
+  }
+}

package.json

@@ -0,0 +1,25 @@
+{
+  "name": "youtubedl",
+  "version": "1.4.5",
+  "license": "SEE LICENSE IN LICENSE",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "test": "node --test tests/extension.test.mjs tests/session.test.mjs tests/ui-connection.test.mjs tests/native-connection.test.mjs tests/history.test.mjs",
+    "test:ui": "node tests/ui.test.mjs",
+    "test:motion": "node tests/progress-motion.test.mjs",
+    "test:setup": "node tests/onboarding.test.mjs",
+    "test:versions": "node tests/version-compatibility.test.mjs",
+    "test:history": "node tests/history-browser.test.mjs",
+    "test:thumbnails": "node tests/thumbnail-placement.test.mjs",
+    "test:live-shorts": "node tests/live-shorts.test.mjs",
+    "test:browser": "node tests/browser-native.test.mjs",
+    "test:helper": "node tests/helper-lifecycle.test.mjs",
+    "test:reconnect": "node tests/helper-reconnect.test.mjs",
+    "test:site": "node tests/site.test.mjs",
+    "check": "node --check extension/background.js && node --check extension/controls.js && node --check extension/content.js && node --check extension/downloader.js && node --check extension/onboarding.js && node --check extension/ui-connection.js"
+  },
+  "devDependencies": {
+    "playwright": "^1.64.0"
+  }
+}

requirements.txt

@@ -0,0 +1 @@
+yt-dlp[default]>=2026.8.19

site/app.js

@@ -0,0 +1,35 @@
+const root = document.documentElement;
+const systemDark = matchMedia("(prefers-color-scheme: dark)");
+const currentTheme = () => root.dataset.theme || (systemDark.matches ? "dark" : "light");
+const themeButton = document.getElementById("theme-toggle");
+function labelTheme() { themeButton.setAttribute("aria-label", `Включить ${currentTheme() === "dark" ? "светлую" : "тёмную"} тему`); }
+labelTheme();
+themeButton.addEventListener("click", () => {
+  root.dataset.theme = currentTheme() === "dark" ? "light" : "dark";
+  try { localStorage.setItem("ytdl-site-theme", root.dataset.theme); } catch { /* Session-only theme. */ }
+  labelTheme();
+});
+systemDark.addEventListener("change", labelTheme);
+
+for (const button of document.querySelectorAll("[data-screenshot]")) button.addEventListener("click", () => {
+  const theme = button.dataset.screenshot;
+  const screenshot = document.getElementById("menu-screenshot");
+  screenshot.src = `assets/menu-${theme}.png`;
+  screenshot.alt = `Меню YouTubeDL в ${theme === "dark" ? "тёмной" : "светлой"} теме: качество видео, звук, формат, кодек и папка сохранения`;
+  for (const peer of document.querySelectorAll("[data-screenshot]")) peer.setAttribute("aria-pressed", String(peer === button));
+});
+
+let copyTimer;
+for (const button of document.querySelectorAll("[data-copy]")) button.addEventListener("click", async () => {
+  const status = document.getElementById("copy-status");
+  try { await navigator.clipboard.writeText(button.dataset.copy); status.textContent = `Скопировано: ${button.dataset.copy}`; }
+  catch { status.textContent = `Скопируйте адрес вручную: ${button.dataset.copy}`; }
+  status.hidden = false;
+  clearTimeout(copyTimer); copyTimer = setTimeout(() => { status.hidden = true; }, 5500);
+});
+
+// Content stays visible if JavaScript or IntersectionObserver is unavailable.
+if ("IntersectionObserver" in window && !matchMedia("(prefers-reduced-motion: reduce)").matches) {
+  const observer = new IntersectionObserver(entries => { for (const entry of entries) if (entry.isIntersecting) { entry.target.classList.add("shown"); observer.unobserve(entry.target); } }, { threshold: 0.07 });
+  for (const element of document.querySelectorAll(".reveal")) { element.classList.add("will-reveal"); observer.observe(element); }
+}

site/assets/mark.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 48 48"><rect width="48" height="48" rx="13" fill="#39bdeb"/><path d="M24 10v20m-8-8 8 8 8-8M12 31v7h24v-7" fill="none" stroke="#0d2b38" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/></svg>

site/index.html

@@ -0,0 +1,102 @@
+<!doctype html>
+<html lang="ru">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <meta name="color-scheme" content="light dark">
+  <meta name="description" content="YouTubeDL — расширение для Edge и Chrome на Windows. Скачивайте видео и Shorts, выбирайте качество, сохраняйте аудио и конвертируйте локально с NVIDIA NVENC или AMD AMF.">
+  <meta name="theme-color" content="#10161d">
+  <meta property="og:title" content="YouTubeDL — Видео. Звук. Ваш выбор.">
+  <meta property="og:description" content="Кнопка скачивания прямо на YouTube. Качество, звук, формат и папка под вашим контролем. Расширение и отдельный помощник для Windows.">
+  <meta property="og:type" content="website">
+  <meta property="og:url" content="https://git.lonarpgproxy.space/extention/youtubedl/">
+  <meta property="og:image" content="https://git.lonarpgproxy.space/extention/youtubedl/assets/github-cover.png">
+  <meta property="og:locale" content="ru_RU">
+  <meta name="twitter:card" content="summary_large_image">
+  <link rel="canonical" href="https://git.lonarpgproxy.space/extention/youtubedl/">
+  <link rel="icon" type="image/svg+xml" href="assets/mark.svg">
+  <title>YouTubeDL — Видео. Звук. Ваш выбор.</title>
+  <script src="theme.js"></script>
+  <link rel="stylesheet" href="styles.css">
+  <script src="app.js" defer></script>
+</head>
+<body>
+  <a class="skip" href="#main">Перейти к содержимому</a>
+  <header class="site-header">
+    <div class="wrap header-inner">
+      <a class="brand" href="#" aria-label="YouTubeDL — начало"><img src="assets/mark.svg" alt="" width="34" height="34"><span>YouTubeDL</span></a>
+      <nav aria-label="Основная навигация"><a href="#features">Возможности</a><a href="#install">Установка</a><a href="#privacy">Данные</a><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL" target="_blank" rel="noopener noreferrer">Gitea <span aria-hidden="true">↗</span></a></nav>
+      <button class="theme-button" id="theme-toggle" type="button" aria-label="Переключить тему" title="Переключить тему"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.7" aria-hidden="true"><path d="M20.4 13A8.5 8.5 0 0 1 11 3.6 8.5 8.5 0 1 0 20.4 13Z"/></svg></button>
+    </div>
+  </header>
+  <main id="main">
+    <section class="hero" aria-labelledby="hero-title">
+      <img class="hero-art" src="assets/hero.png" alt="" fetchpriority="high" width="1774" height="887">
+      <div class="wrap hero-inner">
+        <div class="hero-copy">
+          <p class="overline hero-overline"><span class="live-dot" aria-hidden="true"></span> ДЛЯ EDGE И CHROME · WINDOWS</p>
+          <h1 id="hero-title">Из YouTube.<br>В <span>вашу папку.</span></h1>
+          <p class="hero-description">Ролики, Shorts или только звук.<br>Выберите качество и формат —<br>остальное сделает YouTubeDL.</p>
+          <div class="hero-actions"><a class="button primary" href="#install">Установить расширение <span aria-hidden="true">↓</span></a><a class="hero-link" href="#features">Посмотреть возможности <span aria-hidden="true">↗</span></a></div>
+          <p class="hero-note">Бесплатно · Для Windows · Обработка на вашем компьютере</p>
+        </div>
+        <div class="hero-bottom"><span>ВИДЕО. ЗВУК. ВАШ ВЫБОР.</span><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/tag/v1.4.5">Выпуск 1.4.5 <span aria-hidden="true">↗</span></a></div>
+      </div>
+    </section>
+    <div class="format-strip"><div class="wrap"><p>Один ролик.<br><strong>Ваш формат.</strong></p><div class="format-list" aria-label="Форматы"><span>MP4</span><span>MKV</span><span>WebM</span><i aria-hidden="true"></i><span>MP3</span><span>M4A</span><span>Opus</span><span>FLAC</span><span>WAV</span></div></div></div>
+    <section class="section wrap product-section" id="features" aria-labelledby="features-title">
+      <div class="product-copy reveal">
+        <p class="overline">01 / ВСЁ ПОД РУКОЙ</p>
+        <h2 id="features-title">Один клик.<br>Именно <em>ваши</em><br>настройки.</h2>
+        <p class="section-lead">Кнопка «Скачать» появляется рядом с «Подписаться», на превью и в Shorts. При нажатии загрузчик использует сохранённые параметры.</p>
+        <div class="control-example" aria-label="Пример кнопок на YouTube"><span><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" aria-hidden="true"><path d="M12 3v12m-5-5 5 5 5-5M4 15v5h16v-5"/></svg>Скачать</span><span class="gear-example" aria-hidden="true">⚙</span></div>
+        <p class="quiet">Нужно изменить качество, звук или папку? Откройте ⚙ рядом. Без промежуточных меню при каждом скачивании.</p>
+        <ul class="feature-list"><li><b>Качество источника</b><span>Разрешение, FPS, HDR и язык аудио. Вплоть до 4K/8K, если они доступны у ролика.</span></li><li><b>Видео и звук вместе</b><span>Раздельные дорожки автоматически соединяются. Можно сохранить только видео или только аудио.</span></li><li><b>Файл там, где удобно</b><span>Рабочая папка и папка сохранения могут находиться на разных дисках. Совпадающие имена получают номер; готовые файлы не перезаписываются.</span></li></ul>
+      </div>
+      <figure class="product-visual reveal">
+        <div class="visual-toolbar"><span><i aria-hidden="true"></i> ИНТЕРФЕЙС РАСШИРЕНИЯ</span><div class="screenshot-switch" role="group" aria-label="Тема скриншота"><button type="button" data-screenshot="dark" aria-pressed="true">Тёмная</button><button type="button" data-screenshot="light" aria-pressed="false">Светлая</button></div></div>
+        <div class="screenshot-stage"><img id="menu-screenshot" src="assets/menu-dark.png" alt="Меню YouTubeDL в тёмной теме: качество видео, звук, формат, кодек и папка сохранения" width="520" height="892" loading="lazy"></div>
+        <figcaption>Настоящий интерфейс с тестовыми метаданными.<br>Тема меню подстраивается под YouTube; её можно сменить вручную.</figcaption>
+      </figure>
+    </section>
+    <section class="processing-section" aria-labelledby="processing-title"><div class="wrap processing-inner">
+      <div class="reveal"><p class="overline">02 / БЕЗ ЛИШНИХ ДЕЙСТВИЙ</p><h2 id="processing-title">Две дорожки.<br><em>Один готовый файл.</em></h2><p class="section-lead">Помощник скачивает видео и звук, соединяет их и при необходимости меняет формат. Вы видите каждый этап.</p><p class="quiet">Две операции одновременно, отмена и «Показать файл». Закрытие меню не прерывает скачивание. История загрузок и ошибок открывается в отдельной вкладке.</p></div>
+      <div class="pipeline reveal" aria-label="Этапы обработки"><div class="tracks"><span><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" aria-hidden="true"><rect x="3" y="5" width="18" height="14" rx="3"/><path d="m10 9 5 3-5 3Z"/></svg>Видео</span><span><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" aria-hidden="true"><path d="M5 10v4m4-8v12m4-15v18m4-14v10m4-6v2"/></svg>Звук</span></div><div class="pipeline-line" aria-hidden="true"></div><div class="merged-file"><img src="assets/mark.svg" alt="" width="36" height="36"><div><b>Готовый файл</b><small>В вашей папке</small></div><span aria-hidden="true">✓</span></div><div class="stages"><span>Скачать</span><span>Объединить</span><span>Сохранить</span></div><p>Совместимые дорожки копируются без перекодирования — это обычно быстрее всего.</p></div>
+    </div></section>
+    <section class="section wrap gpu-section" aria-labelledby="gpu-title">
+      <div class="gpu-intro reveal"><p class="overline">03 / ЖЕЛЕЗО ИМЕЕТ ЗНАЧЕНИЕ</p><h2 id="gpu-title">Если конвертировать,<br>то <em>с ускорением.</em></h2><p class="section-lead">NVIDIA NVENC и AMD AMF для H.264, HEVC и AV1. YouTubeDL определяет карту и проверяет кодировщики пробным запуском FFmpeg.</p></div>
+      <div class="gpu-facts reveal"><article><span class="fact-number">01</span><div><h3>Проверка, а не наклейка</h3><p>В меню показаны реальная карта и доступные кодеки. В «Авто» при необходимости используется CPU.</p></div></article><article><span class="fact-number">02</span><div><h3>GPU ускоряет конвертацию</h3><p>Скачивание зависит от сети и YouTube. Аудио и VP9 обрабатываются процессором.</p></div></article><article><span class="fact-number">03</span><div><h3>Честно о проверках</h3><p>NVENC проверен на RTX 5080. AMD AMF реализован; успешное кодирование на физической AMD-карте пока не проверено.</p></div></article></div>
+    </section>
+    <section class="install-section" id="install" aria-labelledby="install-title"><div class="wrap">
+      <div class="install-heading reveal"><div><p class="overline">04 / НАЧНЁМ</p><h2 id="install-title">Два скачивания.<br><em>Один комплект.</em></h2></div><p>Windows 10/11 x64<br>Edge или Chrome 120+<br><span>Без прав администратора</span></p></div>
+      <div class="download-grid reveal">
+        <article class="download-card"><div class="download-card-top"><span class="package-number">1</span><span class="package-tag">БРАУЗЕР</span><span class="version">v1.4.5</span></div><h3>Расширение</h3><p>Кнопки на YouTube, настройки и уведомления. Устанавливается распакованным.</p><a class="button primary package-link" data-download="extension" href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/download/v1.4.5/YouTubeDL-1.4.5.zip">Скачать расширение <span aria-hidden="true">↓</span></a><small>ZIP · <span id="extension-size">Небольшой архив</span></small></article>
+        <article class="download-card helper-card"><div class="download-card-top"><span class="package-number">2</span><span class="package-tag">КОМПЬЮТЕР</span><span class="version">v1.3.2</span></div><h3>Локальный помощник</h3><p>Скачивает, соединяет и конвертирует. Все необходимые компоненты уже внутри.</p><a class="button secondary package-link" data-download="helper" href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/download/v1.4.5/YouTubeDL-Helper-Setup.exe">Скачать помощник <span aria-hidden="true">↓</span></a><small>EXE · 124,3 МиБ · устанавливается отдельно</small></article>
+      </div>
+      <p class="download-note">Оба файла размещены в <a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest">релизах Gitea ↗</a>. Помощник не встроен в ZIP. <a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/INSTALL.md#проверка-скачанных-файлов">Проверка SHA256 и подробности</a>.</p>
+      <ol class="install-steps reveal">
+        <li><span>01</span><div><h3>Распакуйте и загрузите расширение</h3><p>Оставьте распакованный ZIP в постоянной папке. Откройте страницу расширений, включите «Режим разработчика» → «Загрузить распакованное расширение» → выберите папку <code>extension</code>.</p><div class="browser-addresses"><button type="button" class="copy-address" data-copy="edge://extensions">edge://extensions <span>Копировать</span></button><button type="button" class="copy-address" data-copy="chrome://extensions">chrome://extensions <span>Копировать</span></button></div></div></li>
+        <li><span>02</span><div><h3>Запустите помощник</h3><p>Откройте отдельно скачанный <code>YouTubeDL-Helper-Setup.exe</code>. Дождитесь установки. Python, yt-dlp, EJS, Node.js, FFmpeg и FFprobe уже в комплекте; для установки после скачивания интернет не нужен.</p></div></li>
+        <li><span>03</span><div><h3>Обновите YouTube и пройдите мастер</h3><p>Откройте ⚙, нажмите «Проверить подключение», выберите папку, качество и формат. Зелёный индикатор подтверждает реальный ответ помощника. Затем загрузчик будет использовать эти настройки.</p></div></li>
+      </ol>
+      <p class="full-guide"><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/INSTALL.md">Полная инструкция, обновление и удаление <span aria-hidden="true">↗</span></a></p>
+    </div></section>
+    <section class="section wrap privacy-section" id="privacy" aria-labelledby="privacy-title">
+      <div class="reveal"><p class="overline">05 / ПОНЯТНО О ДАННЫХ</p><h2 id="privacy-title">Ваш компьютер.<br><em>Ваша обработка.</em></h2><p class="section-lead">У проекта нет аналитики, рекламы и сервера для конвертации ваших роликов. Исходники доступны для просмотра.</p><a class="text-link" href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/PRIVACY.md">Прочитать полный список данных и разрешений ↗</a></div>
+      <dl class="privacy-facts reveal"><div><dt>Что остаётся локально</dt><dd>Настройки, папка и до 30 последних операций в браузере: названия, ссылки, статусы, пути и ошибки. Помощник отдельно хранит до 30 готовых загрузок. GPU и версии компонентов проверяются для работы приложения.</dd></div><div><dt>Вход — только по согласию</dt><dd>Доступ к cookies YouTube необязателен. Они передаются локальному помощнику и используются в запросах к YouTube; в файлы cookies и историю не записываются. Разрешение можно отозвать.</dd></div><div><dt>Куда идут запросы</dt><dd>К YouTube и его медиасерверам, к официальным источникам обновлений и GitHub для скачиваний и сайта. Эти сервисы видят обычные данные сетевого запроса, включая IP.</dd></div></dl>
+    </section>
+    <section class="faq-section"><div class="wrap faq-inner"><div><p class="overline">ОСТАЛИСЬ ДЕТАЛИ?</p><h2>Частые вопросы.</h2><p class="quiet">Если ответа здесь нет,<br><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/issues">напишите в задачи проекта ↗</a></p></div><div class="faqs">
+      <details><summary>Почему нужен отдельный помощник?<span aria-hidden="true">+</span></summary><p>Браузерное расширение не может запускать FFmpeg и напрямую работать с произвольной папкой Windows. Локальный Native Messaging помощник выполняет скачивание и обработку. Все зависимости собраны в один EXE; отдельно устанавливать Python или FFmpeg не нужно.</p></details>
+      <details><summary>Как работают обновления?<span aria-hidden="true">+</span></summary><p>Обновление компонентов проверяет и скачивает совместимые обновления Python, Node.js, yt-dlp с библиотеками, EJS и FFmpeg/FFprobe. Автопроверка включена по умолчанию: раз в сутки, пока помощник работает, между операциями. Её можно выключить. Новые версии самого расширения и кода помощника устанавливаются вручную из Releases.</p></details>
+      <details><summary>Нужно входить в YouTube?<span aria-hidden="true">+</span></summary><p>Для многих открытых роликов — нет. Если YouTube требует вход или проверку, откройте ролик в текущем профиле и при необходимости включите «Использовать вход в YouTube». Вход на сайте сам по себе не авторизует отдельный загрузчик. Авторизация не гарантирует обход ограничений.</p></details>
+      <details><summary>Будет ли работать 4K, 8K и HDR?<span aria-hidden="true">+</span></summary><p>Если эти дорожки есть у источника. Разрешение не увеличивается искусственно. Для HDR используйте исходный кодек, HEVC или AV1; HDR → H.264 без тонального преобразования отклоняется. FLAC/WAV тоже не восстанавливают уже потерянное качество звука.</p></details>
+      <details><summary>Как удалить всё?<span aria-hidden="true">+</span></summary><p>Удалите помощник кнопкой в меню или через приложения Windows, затем расширение из браузера. Скачанные файлы и история помощника сохраняются. Для удаления истории после удаления помощника удалите <code>%LOCALAPPDATA%\YouTubeDL\Helper\data</code>. Настройки расширения удаляются вместе с расширением.</p></details>
+      <details><summary>Есть другие ОС или магазин расширений?<span aria-hidden="true">+</span></summary><p>Сейчас опубликована сборка для Windows 10/11 x64 и Edge/Chrome 120+. Firefox, macOS, Linux и Windows ARM не входят в неё. В магазинах браузеров расширение пока не опубликовано. Плейлисты, скачивание каналов и DRM-контент не заявляются.</p></details>
+      <details><summary>Можно изменять расширение и публиковать свои версии?<span aria-hidden="true">+</span></summary><p><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/LICENSE">Лицензия</a> разрешает использование по назначению и запрещает изменения, самостоятельные форки и распространение собственного кода без письменного разрешения, с учётом исключений в её тексте. Сторонние компоненты сохраняют свои лицензии.</p></details>
+    </div></div></section>
+    <section class="closing"><div class="wrap"><img src="assets/mark.svg" alt="" width="48" height="48"><h2>Видео. Звук.<br><span>Ваш выбор.</span></h2><a class="button primary" href="#install">Скачать YouTubeDL <span aria-hidden="true">↓</span></a></div></section>
+  </main>
+  <footer class="site-footer"><div class="wrap footer-top"><a class="brand" href="#"><img src="assets/mark.svg" alt="" width="28" height="28"><span>YouTubeDL</span></a><div><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL">Исходники ↗</a><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/PRIVACY.md">Данные</a><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/LICENSE">Лицензия</a><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/src/branch/main/THIRD_PARTY.md">Компоненты</a><a href="https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/issues">Поддержка</a></div></div><div class="wrap footer-bottom"><p>© 2026 OwnerLink. YouTubeDL распространяется по ограниченной пользовательской лицензии.</p><p>Независимый проект. Не связан с YouTube/Google, NVIDIA или AMD. Сохраняйте контент, который вы вправе скачивать.</p><p>На сайте нет счётчиков и собственных cookies. Хостинг — собственный сервер проекта.</p></div></footer>
+  <div id="copy-status" class="copy-status" role="status" aria-live="polite" hidden></div>
+</body>
+</html>

site/robots.txt

@@ -0,0 +1,3 @@
+User-agent: *
+Allow: /
+Sitemap: https://git.lonarpgproxy.space/extention/youtubedl/sitemap.xml

site/sitemap.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><url><loc>https://git.lonarpgproxy.space/extention/youtubedl/</loc></url></urlset>

site/styles.css

@@ -0,0 +1,35 @@
+@layer base, layout, components, responsive;
+@layer base {
+  :root{color-scheme:light;--paper:#f6f6f2;--surface:#fff;--ink:#18232a;--muted:#5b686f;--line:#dce1de;--soft:#e9eeeb;--cyan:#39bdeb;--accent:#007b98;--radius:20px;font-family:Inter,"Segoe UI",Arial,sans-serif;font-synthesis:none}
+  @media(prefers-color-scheme:dark){:root:not([data-theme="light"]){color-scheme:dark;--paper:#10171d;--surface:#182129;--ink:#ecf2f4;--muted:#a5b4bd;--line:#2d3a43;--soft:#1a262d;--accent:#71d9ef}}
+  :root[data-theme="dark"]{color-scheme:dark;--paper:#10171d;--surface:#182129;--ink:#ecf2f4;--muted:#a5b4bd;--line:#2d3a43;--soft:#1a262d;--accent:#71d9ef}
+  *{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:94px}body{margin:0;background:var(--paper);color:var(--ink);line-height:1.6}a{color:inherit;text-decoration:none}button{font:inherit;cursor:pointer}img{max-width:100%;display:block}svg{width:22px;height:22px;flex-shrink:0}button,a{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--cyan);outline-offset:5px}button{color:inherit}h1,h2,h3,p,figure{margin:0}h1,h2{line-height:1.05;letter-spacing:-.055em;font-weight:650}h2{font-size:clamp(36px,4.1vw,58px)}h3{line-height:1.25;font-weight:650}em{font-style:normal;color:var(--accent)}[hidden]{display:none!important}code{font-family:Consolas,monospace;font-size:.88em;overflow-wrap:anywhere}::selection{background:#39bdeb;color:#0b202b}
+  .skip{position:fixed;top:8px;left:16px;z-index:100;background:var(--cyan);color:#0a2633;padding:10px 18px;transform:translateY(-150%)}.skip:focus{transform:none}
+  .wrap{width:min(1180px,calc(100% - 96px));margin-inline:auto}.section{padding-block:110px}.overline{font-size:11px;font-weight:700;letter-spacing:.16em;color:var(--muted);margin-bottom:24px}.section-lead{font-size:18px;color:var(--muted);line-height:1.7;max-width:490px;margin-top:30px}.quiet{font-size:14px;color:var(--muted);line-height:1.75}.text-link{display:inline-block;font-size:14px;font-weight:600;border-bottom:1px solid var(--line);padding-block:5px;margin-top:28px;color:var(--accent)}a:hover{color:var(--accent)}.will-reveal{opacity:0;transform:translateY(18px);transition:opacity .65s,transform .65s}.will-reveal.shown{opacity:1;transform:none}
+}
+@layer layout {
+  .site-header{background:var(--paper);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}.header-inner{display:flex;align-items:center;gap:30px;min-height:78px}.brand{display:inline-flex;align-items:center;gap:10px;font-size:20px;font-weight:750;letter-spacing:-.035em;white-space:nowrap}.header-inner nav{display:flex;gap:30px;margin-left:auto;font-size:13px;font-weight:600}.header-inner nav a{padding-block:12px}.theme-button{width:36px;height:36px;display:grid;place-items:center;flex-shrink:0;border:1px solid var(--line);background:transparent;border-radius:50%}.theme-button:hover{background:var(--soft)}
+  .hero{position:relative;overflow:hidden;background:#10161d;color:#eff7fa;min-height:640px}.hero-art{position:absolute;height:100%;width:100%;max-width:none;object-fit:cover;object-position:center right;opacity:.85}.hero:after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,#10161d 0%,#10161de6 25%,transparent 57%);pointer-events:none}.hero-inner{position:relative;z-index:1;min-height:640px;display:flex;flex-direction:column}.hero-copy{padding-top:76px;max-width:540px}.hero-overline{color:#aac1cd;margin-bottom:28px;display:flex;align-items:center;gap:9px}.live-dot{width:6px;height:6px;background:#79e3d1;border-radius:50%}.hero h1{font-size:clamp(46px,5.9vw,82px)}.hero h1 span{color:#8de7e1}.hero-description{font-size:18px;color:#bed0db;line-height:1.7;margin-top:27px}.hero-actions{display:flex;align-items:center;gap:23px;flex-wrap:wrap;margin-top:32px}.hero-link{font-size:12px;color:#d4e4ed}.hero-link:hover{color:#91eee2}.hero-note{font-size:11px;color:#8cabbc;margin-top:19px}.hero-bottom{margin-top:auto;padding:32px 0 22px;display:flex;justify-content:space-between;align-items:center;color:#7f9ba8;font-size:10px;letter-spacing:.15em}.hero-bottom a{letter-spacing:0;color:#bfced6;font-size:12px}
+  .format-strip{border-bottom:1px solid var(--line)}.format-strip>.wrap{display:flex;align-items:center;gap:66px;min-height:115px}.format-strip p{font-size:12px;color:var(--muted);line-height:1.5;white-space:nowrap}.format-strip strong{color:var(--ink)}.format-list{display:flex;align-items:center;justify-content:space-between;gap:26px;width:100%;font-size:19px;letter-spacing:-.035em;font-weight:650;color:var(--muted)}.format-list i{width:1px;height:22px;background:var(--line);flex-shrink:0}
+  .product-section{display:grid;grid-template-columns:1fr 1fr;gap:98px;align-items:start}.product-copy .section-lead{font-size:16px}.product-copy .quiet{max-width:390px}.product-visual{padding-top:8px;min-width:0}.visual-toolbar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:18px;font-size:9px;letter-spacing:.12em;color:var(--muted);white-space:nowrap}.visual-toolbar>span{display:flex;align-items:center;gap:7px}.visual-toolbar i{width:5px;height:5px;border-radius:50%;background:var(--accent)}.screenshot-stage{background:#dae5e3;padding:22px;border-radius:26px;box-shadow:0 20px 45px #102b3810}.screenshot-stage img{width:100%;height:auto;border-radius:13px;border:1px solid #ffffff18;box-shadow:0 10px 25px #08101a30}.product-visual figcaption{font-size:11px;line-height:1.7;color:var(--muted);margin-top:18px;text-align:center}
+  .processing-section{background:var(--soft);border-block:1px solid var(--line);padding-block:92px}.processing-inner{display:grid;grid-template-columns:1fr 1fr;gap:110px;align-items:center}.processing-inner .quiet{max-width:420px;margin-top:20px}.gpu-section{display:grid;grid-template-columns:1fr 1fr;gap:100px;align-items:start}.gpu-facts{padding-top:35px}.gpu-facts article{display:flex;gap:25px;padding:25px 0;border-top:1px solid var(--line)}.gpu-facts h3{font-size:18px;margin-bottom:10px}.gpu-facts p{font-size:14px;color:var(--muted);line-height:1.75}.fact-number{font-size:12px;color:var(--accent);padding-top:2px;font-family:Consolas,monospace}
+  .install-section{background:var(--surface);padding-block:95px;border-block:1px solid var(--line)}.install-heading{display:flex;justify-content:space-between;gap:25px;align-items:end;margin-bottom:45px}.install-heading>p{font-size:14px;color:var(--muted);line-height:1.9;text-align:right}.install-heading>p span{font-size:12px}.download-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.download-note{font-size:12px;color:var(--muted);line-height:1.8;max-width:880px;margin-top:20px}.download-note a{text-decoration:underline;text-underline-offset:3px}.install-steps{list-style:none;padding:0;margin:55px 0 0;counter-reset:steps}.install-steps li{display:grid;grid-template-columns:85px 1fr;gap:25px;padding:32px 0;border-top:1px solid var(--line)}.install-steps li>span{font-size:32px;line-height:1.2;letter-spacing:-.05em;color:var(--accent)}.install-steps h3{font-size:20px;margin-bottom:10px}.install-steps p{font-size:14px;color:var(--muted);max-width:800px}.browser-addresses{display:flex;gap:12px;margin-top:17px;flex-wrap:wrap}.full-guide{font-size:14px;padding-top:12px;color:var(--accent)}
+  .privacy-section{display:grid;grid-template-columns:1fr 1fr;gap:100px}.privacy-facts{margin:20px 0 0}.privacy-facts>div{padding:22px 0;border-top:1px solid var(--line)}.privacy-facts dt{font-weight:650;font-size:17px;margin-bottom:10px}.privacy-facts dd{margin:0;font-size:14px;color:var(--muted);line-height:1.8}.faq-section{padding-block:75px;border-top:1px solid var(--line)}.faq-inner{display:grid;grid-template-columns:.85fr 1.15fr;gap:100px}.faq-inner h2{font-size:38px}.faq-inner .quiet{margin-top:25px}.faq-inner .quiet a{color:var(--accent)}.closing{background:#10161d;color:#f1f8fa;text-align:center;padding:76px 0 83px;overflow:hidden}.closing img{margin:0 auto 25px}.closing h2{font-size:clamp(40px,5vw,62px);margin-bottom:32px}.closing h2 span{color:#8de7e1}.site-footer{padding-block:30px 35px}.footer-top{display:flex;justify-content:space-between;gap:30px;align-items:center;padding-bottom:25px;border-bottom:1px solid var(--line)}.footer-top .brand{font-size:17px}.footer-top>div{display:flex;flex-wrap:wrap;gap:24px;font-size:12px}.footer-bottom{padding-top:20px;font-size:11px;color:var(--muted);line-height:1.9}.footer-bottom p+p{margin-top:5px}
+}
+@layer components {
+  .button{display:inline-flex;align-items:center;justify-content:center;gap:24px;min-height:51px;padding:13px 24px;border-radius:9px;font-size:13px;font-weight:700;line-height:1.4;border:1px solid transparent;transition:background .18s,box-shadow .18s}.button.primary{background:var(--cyan);color:#082937}.button.primary:hover{background:#6bceee;box-shadow:0 4px 14px #39bdeb22}.button.secondary{background:var(--ink);color:var(--paper)}.button.secondary:hover{opacity:.9}.button span{font-size:22px;line-height:1}
+  .control-example{display:flex;align-items:center;gap:8px;margin:25px 0 13px}.control-example>span{display:inline-flex;align-items:center;justify-content:center;gap:10px;background:var(--soft);border:1px solid var(--line);height:40px;padding-inline:18px;border-radius:22px;font-size:14px;font-weight:650}.control-example svg{width:19px;height:19px}.control-example>.gear-example{width:40px;padding:0;font-size:23px}
+  .feature-list{list-style:none;margin:28px 0 0;padding:0}.feature-list li{padding:18px 0;border-top:1px solid var(--line)}.feature-list b{display:block;font-size:15px;font-weight:650}.feature-list span{display:block;font-size:13px;color:var(--muted);line-height:1.8;margin-top:6px}
+  .screenshot-switch{display:flex;gap:3px;background:var(--soft);padding:3px;border-radius:8px;letter-spacing:0}.screenshot-switch button{font-size:10px;border:0;background:transparent;padding:5px 10px;border-radius:5px;color:var(--muted)}.screenshot-switch [aria-pressed="true"]{background:var(--surface);color:var(--ink);box-shadow:0 1px 3px #0001}
+  .pipeline{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:34px 38px}.tracks{display:flex;gap:14px}.tracks>span{display:flex;align-items:center;justify-content:center;gap:12px;background:var(--soft);border:1px solid var(--line);border-radius:10px;min-height:70px;flex:1;font-size:15px}.tracks svg{color:var(--accent);width:25px;height:25px}.pipeline-line{height:45px;width:52%;margin:auto;border:1px solid var(--line);border-top:0;border-radius:0 0 12px 12px;position:relative}.pipeline-line:after{content:"";position:absolute;left:50%;top:100%;height:18px;border-left:1px solid var(--line)}.merged-file{display:flex;align-items:center;gap:13px;margin-top:18px;background:var(--soft);border:1px solid var(--line);border-radius:10px;padding:19px}.merged-file b{display:block;font-size:15px}.merged-file small{display:block;font-size:11px;color:var(--muted);margin-top:2px}.merged-file>span{margin-left:auto;color:var(--accent);font-size:21px}.stages{display:flex;gap:4px;padding-top:24px}.stages span{flex:1;font-size:10px;color:var(--muted);border-top:3px solid #61c6d2;padding-top:7px}.stages span:nth-child(2){border-color:#92ddd8}.stages span:nth-child(3){border-color:#bcded4}.pipeline>p{font-size:11px;line-height:1.8;color:var(--muted);margin-top:18px}
+  .download-card{border:1px solid var(--line);border-radius:15px;padding:28px;background:var(--paper);min-width:0;display:flex;flex-direction:column}.download-card-top{display:flex;align-items:center;gap:12px;margin-bottom:25px}.package-number{width:30px;height:30px;display:grid;place-items:center;background:var(--soft);border-radius:50%;font-weight:650;font-size:13px}.package-tag{font-size:10px;font-weight:600;letter-spacing:.12em;color:var(--muted)}.version{margin-left:auto;font-family:Consolas,monospace;font-size:12px;color:var(--muted)}.download-card h3{font-size:28px;letter-spacing:-.04em;margin-bottom:13px}.download-card p{font-size:14px;color:var(--muted);line-height:1.75;max-width:380px;margin-bottom:25px}.download-card .button{margin-top:auto;width:100%;justify-content:space-between}.download-card small{font-size:11px;color:var(--muted);margin-top:12px;text-align:center}.helper-card{background:var(--surface)}
+  .copy-address{background:var(--paper);border:1px solid var(--line);border-radius:7px;padding:9px 12px;display:flex;align-items:center;gap:14px;font-family:Consolas,monospace;font-size:11px}.copy-address span{font-family:"Segoe UI",sans-serif;font-size:10px;color:var(--accent)}.copy-address:hover{background:var(--soft)}.copy-status{position:fixed;bottom:25px;left:50%;transform:translateX(-50%);z-index:20;border:1px solid var(--line);background:var(--ink);color:var(--paper);box-shadow:0 5px 35px #0002;padding:12px 20px;border-radius:10px;font-size:13px;max-width:calc(100% - 32px);width:max-content}
+  .faqs details{border-bottom:1px solid var(--line)}.faqs details:first-child{border-top:1px solid var(--line)}.faqs summary{display:flex;align-items:center;justify-content:space-between;gap:18px;list-style:none;cursor:pointer;font-size:15px;font-weight:650;line-height:1.5;padding:21px 0}.faqs summary::-webkit-details-marker{display:none}.faqs summary span{color:var(--accent);font-size:22px;font-weight:400;transition:transform .2s}.faqs details[open] summary span{transform:rotate(45deg)}.faqs details p{font-size:13px;color:var(--muted);line-height:1.85;padding:0 24px 23px 0}
+}
+@layer responsive {
+  @media(min-width:1600px){.hero-art{object-position:center;object-fit:contain}}
+  @media(max-width:1000px){.wrap{width:calc(100% - 56px)}.section{padding-block:80px}.product-section,.processing-inner,.gpu-section,.privacy-section,.faq-inner{gap:45px}.header-inner nav{gap:20px}.hero-art{object-position:57% center;opacity:.64}.hero:after{background:linear-gradient(90deg,#10161df5 0%,#10161daa 32%,transparent 85%)}.hero h1{font-size:64px}.format-strip>.wrap{gap:30px}.format-list{font-size:16px;gap:16px}.screenshot-stage{padding:14px}.visual-toolbar>span{font-size:8px;letter-spacing:.05em}.screenshot-switch button{padding:5px 7px}.pipeline{padding:25px}.install-heading h2{font-size:46px}}
+  @media(max-width:700px){.wrap{width:calc(100% - 40px)}html{scroll-padding-top:115px}.section{padding-block:65px}.header-inner{gap:12px;min-height:98px;flex-wrap:wrap;padding:13px 0 9px}.header-inner>.brand{font-size:18px}.header-inner>.brand img{width:29px;height:29px}.header-inner nav{order:3;width:100%;gap:0;justify-content:space-between;font-size:11px}.header-inner nav a{padding-block:4px}.theme-button{margin-left:auto;width:31px;height:31px}.hero,.hero-inner{min-height:720px}.hero-copy{padding-top:42px;max-width:420px}.hero h1{font-size:clamp(47px,10.5vw,66px)}.hero-overline{font-size:9px;margin-bottom:22px}.hero-description{font-size:16px;margin-top:23px}.hero-actions{margin-top:25px;gap:16px}.hero-actions .button{font-size:12px;padding-inline:18px}.hero-link{font-size:11px}.hero-note{font-size:10px;max-width:290px;line-height:1.8}.hero-art{height:59%;width:118%;bottom:10px;right:-9%;object-position:center;opacity:.7}.hero:after{background:linear-gradient(180deg,#10161d 0%,#10161de6 35%,#10161d77 58%,transparent 80%)}.hero-bottom{font-size:8px;padding-bottom:17px}.hero-bottom a{font-size:10px}.format-strip>.wrap{padding-block:20px;min-height:0;gap:20px}.format-strip p{font-size:10px}.format-list{font-size:14px;justify-content:flex-start;gap:12px;flex-wrap:wrap}.format-list i{display:none}.product-section,.processing-inner,.gpu-section,.privacy-section,.faq-inner{grid-template-columns:1fr;gap:36px}.product-copy h2 br:nth-of-type(2){display:none}h2{font-size:41px}.section-lead{font-size:16px;margin-top:22px}.product-copy .quiet{max-width:none}.feature-list li{padding:16px 0}.visual-toolbar{font-size:9px}.visual-toolbar>span{font-size:9px}.screenshot-switch button{font-size:10px;padding:5px 9px}.product-visual{max-width:480px;justify-self:center;width:100%}.screenshot-stage{padding:16px}.processing-section{padding-block:60px}.pipeline{padding:27px}.gpu-facts{padding-top:0}.gpu-facts article{padding-block:20px}.install-section{padding-block:60px}.install-heading{align-items:start;flex-direction:column;gap:22px;margin-bottom:30px}.install-heading h2{font-size:41px}.install-heading>p{text-align:left;font-size:12px;line-height:1.7}.download-grid{grid-template-columns:1fr;gap:15px}.download-card{padding:23px}.download-card-top{margin-bottom:20px}.download-card h3{font-size:26px}.install-steps{margin-top:35px}.install-steps li{grid-template-columns:35px 1fr;gap:18px;padding:25px 0}.install-steps li>span{font-size:24px}.install-steps h3{font-size:18px}.install-steps p{font-size:13px}.browser-addresses{gap:8px}.copy-address{font-size:10px;gap:10px;padding:9px}.privacy-facts{margin-top:0}.privacy-facts dt{font-size:16px}.faq-section{padding-block:55px}.faq-inner h2{font-size:35px}.faq-inner .quiet br{display:none}.faqs summary{font-size:14px}.closing{padding-block:56px}.footer-top{align-items:start;flex-direction:column;gap:20px}.footer-top>div{gap:20px;font-size:11px}.footer-bottom{font-size:10px}}
+  @media(max-width:360px){h2,.install-heading h2{font-size:35px}.hero h1{font-size:44px}.visual-toolbar{flex-wrap:wrap}.product-section,.processing-inner,.gpu-section,.privacy-section,.faq-inner{grid-template-columns:minmax(0,1fr)}}
+  @media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation:none!important;transition:none!important}.will-reveal{opacity:1;transform:none}}
+}

site/theme.js

@@ -0,0 +1,5 @@
+// Apply the preference before CSS loads; unavailable storage never blocks the page.
+(() => {
+  try { const theme = localStorage.getItem("ytdl-site-theme"); if (["light", "dark"].includes(theme)) document.documentElement.dataset.theme = theme; }
+  catch { /* System theme remains the default. */ }
+})();

tests/amd-fallback.py

@@ -0,0 +1,33 @@
+"""On this NVIDIA machine: real AMF initialization failure and automatic CPU fallback."""
+import contextlib
+import io
+import json
+import subprocess
+import sys
+from pathlib import Path
+
+PROJECT = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(PROJECT))
+from host.media import capabilities, probe, tool
+from host.worker import convert
+
+hardware = capabilities()
+if hardware["amf"]:
+    raise RuntimeError("This negative-path check is intended for a machine without AMD AMF.")
+folder = PROJECT / "test-artifacts/media"; folder.mkdir(parents=True, exist_ok=True)
+source = folder / "amd-fallback-input.mkv"
+subprocess.run([tool("ffmpeg"), "-hide_banner", "-loglevel", "error", "-y", "-f", "lavfi", "-i", "testsrc2=s=320x180:r=24", "-f", "lavfi", "-i", "sine=frequency=440", "-t", "0.4", "-c:v", "libx264", "-c:a", "aac", str(source)], check=True, capture_output=True)
+media = probe(source)
+options = {"mode": "video", "container": "mp4", "codec": "hevc", "engine": "auto", "preset": "fast", "bitrate": 192}
+events = io.StringIO()
+with contextlib.redirect_stdout(events):
+    plan = convert(source, folder / "amd-fallback-result.mp4", options, media, {"amf": ["hevc"]})
+assert plan["engine"] == "cpu"
+assert {item["codec_type"] for item in probe(folder / "amd-fallback-result.mp4")["streams"]} == {"video", "audio"}
+with contextlib.redirect_stdout(io.StringIO()):
+    try: convert(source, folder / "amd-forced-result.mp4", {**options, "engine": "amf"}, media, {"amf": ["hevc"]})
+    except ValueError as error: assert "FFmpeg" in str(error)
+    else: raise AssertionError("Forced AMD mode must not silently use the CPU")
+report = {"gpu": hardware["gpu"], "amfMeasured": hardware["amf"], "nvencMeasured": hardware["nvenc"], "autoFallback": "CPU passed", "forcedAMF": "rejected", "physicalAMDEncoding": "not tested: AMD GPU absent"}
+(PROJECT / "test-artifacts/amd-fallback.json").write_text(json.dumps(report, ensure_ascii=False, indent=2), encoding="utf-8")
+print("AMD negative-path checks passed: real AMF failure, automatic CPU fallback with audio, and forced-mode error.")

tests/browser-components.test.mjs

@@ -0,0 +1,53 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import os from "node:os";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+
+const root=path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts=path.join(root,'test-artifacts');
+await fs.mkdir(artifacts,{recursive:true});
+const profile=await fs.mkdtemp(path.join(os.tmpdir(),'ytdl-components-test-'));
+const context=await chromium.launchPersistentContext(profile,{
+  headless:true,viewport:{width:1000,height:900},
+  executablePath:'C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe',
+  ignoreDefaultArgs:['--disable-extensions'],args:['--enable-unsafe-extension-debugging'],
+});
+try {
+  const cdp=await context.browser().newBrowserCDPSession();
+  const {id}=await cdp.send('Extensions.loadUnpacked',{path:path.join(root,'extension')});
+  const worker=context.serviceWorkers()[0] || await context.waitForEvent('serviceworker');
+  await worker.evaluate(() => chrome.storage.local.set({ onboarding: { state: "complete", version: 1 } }));
+  const page=await context.newPage(); let installerDownloads=0;
+  page.on('download',()=>installerDownloads++);
+  await page.goto(`chrome-extension://${id}/downloader.html`);
+  await page.locator('#helper-panel[data-state="running"]').waitFor({timeout:90000});
+  await page.locator('#helper-panel > summary').click();
+  assert.equal(await page.locator('#helper-install').textContent(),'Переустановить');
+  const automatic=await page.locator('#auto-update').isChecked();
+  if(automatic) await page.locator('#auto-update').uncheck();
+  await page.locator('#helper-update').click();
+  const deadline=Date.now()+240000; let job;
+  while(Date.now()<deadline) {
+    const jobs=await worker.evaluate(async()=>Object.values((await chrome.storage.local.get('jobs')).jobs || {}));
+    job=jobs.find(item=>item.kind==='update');
+    if(job && job.status!=='running') break;
+    await new Promise(resolve=>setTimeout(resolve,200));
+  }
+  assert.ok(job); assert.equal(job.status,'complete',job.error);
+  assert.equal(installerDownloads,0,'Update components must use the helper, not download the embedded EXE');
+  await page.locator('#helper-panel[data-state="running"]').waitFor({timeout:90000});
+  await page.locator('#helper-update:not([disabled])').waitFor({timeout:30000});
+  assert.equal(await page.locator('.dependency-row[data-status="installed"]').count(),5);
+  assert.equal(await page.locator('#engine option[value="nvenc"]').isDisabled(),false);
+  assert.equal(await page.locator('#engine option[value="amf"]').isDisabled(),true);
+  await page.locator('#auto-update').setChecked(automatic);
+  await page.locator('.dependencies summary').click();
+  await page.screenshot({path:path.join(artifacts,'component-updater.png'),animations:'disabled'});
+  await fs.writeFile(path.join(artifacts,'browser-components.json'),JSON.stringify({updateButton:'passed',installerDownloads,job,automatic},null,2));
+  console.log('Browser component update passed: real native request, official version check, completed progress, ready tools, preserved automatic-update setting, no EXE download.');
+} finally {
+  await context.close();
+  if(path.dirname(path.resolve(profile))===path.resolve(os.tmpdir()) && path.basename(profile).startsWith('ytdl-components-test-')) await fs.rm(profile,{recursive:true,force:true});
+}

tests/browser-native.test.mjs

@@ -0,0 +1,106 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import os from "node:os";
+import { execFile } from "node:child_process";
+import { promisify } from "node:util";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+import { installedHelperRoot } from "./installed-helper.mjs";
+
+// Uses a fresh browser profile and the registered native host. No browser accounts.
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const extension = path.join(root, "extension");
+const artifacts = path.join(root, "test-artifacts");
+const folder = path.join(artifacts, "media");
+const videoId = process.env.YTDL_TEST_VIDEO_ID || "jNQXAC9IVRw";
+assert.match(videoId, /^[\w-]{11}$/);
+await fs.mkdir(folder, { recursive: true });
+const profile = await fs.mkdtemp(path.join(os.tmpdir(), "ytdl-browser-test-"));
+const context = await chromium.launchPersistentContext(profile, {
+  headless: true, viewport: { width: 1280, height: 900 },
+  executablePath: process.env.YTDL_TEST_BROWSER || "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe",
+  ignoreDefaultArgs: ["--disable-extensions"], args: ["--enable-unsafe-extension-debugging"],
+});
+try {
+  const cdp = await context.browser().newBrowserCDPSession();
+  const installed = await cdp.send("Extensions.loadUnpacked", { path: extension });
+  assert.equal(installed.id, "ndnoeiaecgmjnjneekaeapeecmmjheli");
+  const worker = context.serviceWorkers()[0] || await context.waitForEvent("serviceworker", { timeout: 30000 });
+  assert.equal(new URL(worker.url()).hostname, "ndnoeiaecgmjnjneekaeapeecmmjheli");
+  await worker.evaluate(() => chrome.storage.local.set({ onboarding: { state: "complete", version: 1 } }));
+  // Only the browser page is a fixture; inspection, streams and NVENC are real.
+  await context.route("https://www.youtube.com/**", route => route.fulfill({
+    contentType: "text/html", body: '<!doctype html><html dark><head><meta charset="utf-8"></head><body style="margin:30px;background:#0f0f0f;color:white;font:14px Segoe UI"><div style="height:340px;background:#182837;border-radius:15px"></div><h1>Me at the zoo</h1><ytd-watch-metadata><div id="owner" style="display:flex;align-items:center"><div id="subscribe-button"><button style="border:0;border-radius:22px;padding:12px 18px">Подписаться</button></div></div></ytd-watch-metadata></body></html>',
+  }));
+  const page = await context.newPage();
+  const errors = [];
+  page.on("pageerror", error => errors.push(error.message));
+  await page.goto(`https://www.youtube.com/watch?v=${videoId}`);
+  await page.locator("#ytdl-subscribe-download .settings").click();
+  const ui = page.frameLocator("#ytdl-menu iframe");
+  try {
+    await Promise.race([
+      ui.locator("#download-form").waitFor({ state: "visible", timeout: 180000 }),
+      ui.locator('#alert:not([hidden])').waitFor({state:'visible',timeout:180000}).then(async()=>{ throw new Error(await ui.locator('#alert').innerText()); }),
+    ]);
+  }
+  catch (error) {
+    console.log('Connection diagnostics:', await ui.locator('body').innerText());
+    console.log('Page errors:', errors);
+    await page.screenshot({path:path.join(artifacts,'browser-native-error.png'),animations:'disabled'});
+    throw error;
+  }
+  assert.match(await ui.locator("#hardware").textContent(), /RTX 5080/);
+  assert.equal(await ui.locator("#helper-status").textContent(), "Помощник работает");
+  assert.match(await ui.locator("#helper-message").textContent(), /Автономный комплект/);
+  assert.equal(await ui.locator('.dependency-row[data-status="installed"]').count(), 5);
+  await page.evaluate(() => document.documentElement.removeAttribute("dark"));
+  await ui.locator('html[data-theme="light"]').waitFor();
+  await page.evaluate(() => document.documentElement.setAttribute("dark", ""));
+  await ui.locator('html[data-theme="dark"]').waitFor();
+  const qualities = await ui.locator("#quality option").evaluateAll(nodes => nodes.map(n => ({ id: n.value, text: n.textContent })));
+  const separate = qualities.filter(q => q.id !== "best" && !q.text.includes("со звуком")).at(-1);
+  assert.ok(separate, "A real separate video stream must be available");
+  await ui.locator("#quality").selectOption(separate.id);
+  await ui.locator("#codec").selectOption("hevc");
+  await ui.locator(".advanced summary").click();
+  await ui.locator("#engine").selectOption("nvenc");
+  await ui.locator("#filename").fill("Browser-native-HEVC");
+  await ui.locator("#folder").fill(folder);
+  await ui.locator("#save-settings").click();
+  try { await page.locator("#ytdl-menu").waitFor({ state: "detached", timeout: 15000 }); }
+  catch (error) {
+    console.log("Menu alert:", await ui.locator("#alert").textContent());
+    console.log("Jobs:", await worker.evaluate(async () => (await chrome.storage.local.get("jobs")).jobs));
+    await page.screenshot({ path: path.join(artifacts, "browser-native-error.png"), animations: "disabled" });
+    throw error;
+  }
+  await page.locator("#ytdl-subscribe-download .download").click();
+  await page.locator("#ytdl-notifications .toast").waitFor();
+  console.log("Real extension connected; download started, on-page toast visible.");
+  await page.locator("#ytdl-notifications .toast.complete, #ytdl-notifications .toast.error").waitFor({ timeout: 240000 });
+  const saved = await worker.evaluate(async () => (await chrome.storage.local.get("jobs")).jobs);
+  const job = Object.values(saved).find(job => job.result?.path && job.url.includes(videoId));
+  assert.ok(job, JSON.stringify(saved));
+  assert.equal(job.status, "complete", job.error);
+  assert.equal(job.result.engine, "nvenc");
+  assert.equal(job.result.codec, "hevc");
+  const installedRoot = await installedHelperRoot();
+  const installedBundle = JSON.parse((await fs.readFile(path.join(installedRoot, "installation.json"), "utf8")).replace(/^\uFEFF/, ""));
+  const bundle = JSON.parse(await fs.readFile(path.join(installedBundle.current, "bundle.json"), "utf8"));
+  const probe = await promisify(execFile)(path.join(installedBundle.current, bundle.tools.ffprobe), ["-v", "error", "-show_streams", "-of", "json", job.result.path]);
+  const streams = JSON.parse(probe.stdout).streams;
+  assert.ok(streams.some(s => s.codec_type === "video" && s.codec_name === "hevc"));
+  assert.ok(streams.some(s => s.codec_type === "audio"));
+  assert.deepEqual(errors, []);
+  await page.screenshot({ path: path.join(artifacts, "browser-native-complete.png"), animations: "disabled" });
+  await fs.writeFile(path.join(artifacts, "browser-native.json"), JSON.stringify({ extensionId: new URL(worker.url()).hostname, job }, null, 2));
+  console.log("Browser/native checks passed: real MV3 extension, native messaging, separate audio, NVENC, saved file, live toast.");
+} finally {
+  await context.close();
+  const resolved = path.resolve(profile);
+  if (path.dirname(resolved) === path.resolve(os.tmpdir()) && path.basename(resolved).startsWith("ytdl-browser-test-")) {
+    await fs.rm(resolved, { recursive: true, force: true });
+  }
+}

tests/component-update.py

@@ -0,0 +1,84 @@
+"""Real staged publication, stale-update rejection and live PyPI wheels, no registry changes."""
+import hashlib
+import json
+import os
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+from unittest.mock import patch
+
+PROJECT = Path(__file__).resolve().parent.parent
+
+
+def inside(packages=False):
+    from host.bundle import ROOT, installation_root
+    from host.updates import update
+    from host.media import capabilities
+    application = installation_root()
+    marker = application / "installation.json"
+    before = json.loads(marker.read_text(encoding="utf-8-sig"))["current"]
+    if packages:
+        import io
+        import time
+        from host.main import NativeHost
+        host = NativeHost(io.BytesIO())
+        try:
+            response = host.start_update([{"id": "packages", "version": "latest-compatible"}])
+            deadline = time.monotonic() + 500
+            while host.jobs[response["jobId"]]["status"] == "running" and time.monotonic() < deadline: time.sleep(0.1)
+            job = host.jobs[response["jobId"]]
+            assert job["status"] == "complete", job
+            result = job["result"]
+        finally: host.close()
+        after = Path(json.loads(marker.read_text(encoding="utf-8-sig"))["current"])
+        versions = json.loads((after / "bundle.json").read_text(encoding="utf-8"))["pythonPackages"]
+        assert result["restartRequired"] and "yt-dlp" in {key.lower() for key in versions}
+        print(json.dumps({"livePyPI": "passed", "nativeWorkerUpdate": "passed", "packages": versions}))
+        return
+    archive = PROJECT / ".build-cache/node.zip"
+    data = archive.read_bytes()
+    candidate = {"id": "node", "version": "v24.21.0", "url": "https://nodejs.org/dist/v24.21.0/node-v24.21.0-win-x64.zip", "sha256": hashlib.sha256(data).hexdigest()}
+    class Response:
+        headers = {"Content-Length": str(len(data))}
+        def __enter__(self): return self
+        def __exit__(self, *args): return False
+        def iter_content(self, count):
+            for offset in range(0, len(data), count): yield data[offset:offset + count]
+    dll = ROOT / "runtime/python/python313.dll"
+    with dll.open("rb") as opened, patch("host.updates.get", return_value=Response()):
+        result = update(lambda *args: None, lambda _: None, [candidate])
+        after = json.loads(marker.read_text(encoding="utf-8-sig"))["current"]
+        assert after != before and result["restartRequired"] and dll.is_file() and opened.read(2) == b"MZ"
+        try: update(lambda *args: None, lambda _: None, [candidate])
+        except ValueError as error: assert "другой установкой" in str(error)
+        else: raise AssertionError("A stale helper must not replace the newer runtime")
+        try: update(lambda *args: None, lambda _: None, [{**candidate, "sha256": "0" * 64}])
+        except ValueError as error: assert "Контрольная сумма" in str(error)
+        else: raise AssertionError("Modified downloads must be rejected")
+        assert json.loads(marker.read_text(encoding="utf-8-sig"))["current"] == after
+    assert not list((application / "releases").glob(".ytdl-update-*")) == [], "The published release must remain"
+    print(json.dumps({"stagedActivation": "passed", "openOldDLL": "preserved", "staleUpdate": "rejected", "badHash": "rejected"}))
+
+
+def outer():
+    artifacts = PROJECT / "test-artifacts"; artifacts.mkdir(exist_ok=True)
+    with tempfile.TemporaryDirectory(prefix="update-test-", dir=artifacts) as temporary:
+        root = Path(temporary) / "Helper"
+        process = subprocess.run([str(PROJECT / "dist/YouTubeDL-Helper-Setup.exe"), "--silent", "--no-register", "--target-root", str(root)], capture_output=True, text=True, encoding="utf-8", timeout=180)
+        assert process.returncode == 0, process.stdout + process.stderr
+        records = []
+        for action in ("--inside", "--inside-packages"):
+            marker = json.loads((root / "installation.json").read_text(encoding="utf-8-sig"))
+            python = Path(marker["current"]) / "runtime/python/python.exe"
+            result = subprocess.run([str(python), "-I", "-X", "utf8", "-B", str(Path(__file__).resolve()), action], capture_output=True, text=True, encoding="utf-8", timeout=600)
+            assert result.returncode == 0, result.stdout[-1000:] + result.stderr[-4000:]
+            records.append(json.loads(result.stdout.splitlines()[-1]))
+        (artifacts / "component-update.json").write_text(json.dumps(records, indent=2), encoding="utf-8")
+        print("Component updates passed: live PyPI downloads, verified stage activation, retained old DLL, bad hash rejection and stale-update rejection.")
+
+
+if __name__ == "__main__":
+    if "--inside" in sys.argv: inside()
+    elif "--inside-packages" in sys.argv: inside(True)
+    else: outer()

tests/extension.test.mjs

@@ -0,0 +1,73 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import crypto from "node:crypto";
+import { canonicalUrl, bytes, duration, progressText, preferenceOptions, stabilizeDownloadSpeed, checkHelperCompatibility } from "../extension/shared.js";
+
+test("URLs accept watch and Shorts but reject arbitrary origins and credentials", () => {
+  assert.equal(canonicalUrl("https://www.youtube.com/shorts/jNQXAC9IVRw"), "https://www.youtube.com/watch?v=jNQXAC9IVRw");
+  assert.equal(canonicalUrl("https://youtu.be/jNQXAC9IVRw?list=123"), "https://www.youtube.com/watch?v=jNQXAC9IVRw");
+  for (const url of ["https://youtube.com.evil/watch?v=jNQXAC9IVRw", "http://youtube.com/watch?v=jNQXAC9IVRw", "https://user@youtube.com/watch?v=jNQXAC9IVRw"]) assert.equal(canonicalUrl(url), null);
+});
+test("progress labels distinguish download tracks and GPU conversion", () => {
+  assert.equal(progressText({ stage: "downloading", track: "audio" }), "Скачивание · аудио");
+  assert.equal(progressText({ stage: "encoding", engine: "nvenc" }), "Перекодирование · NVIDIA NVENC");
+  assert.equal(progressText({ stage: "encoding", engine: "amf" }), "Перекодирование · AMD AMF");
+  assert.equal(progressText({ stage: "encoding", engine: "cpu" }), "Перекодирование · CPU");
+  assert.equal(progressText({ stage: "merging", engine: "copy" }), "Объединение дорожек · без перекодирования");
+  assert.equal(progressText({ stage: "remuxing", engine: "copy" }), "Подготовка файла · без перекодирования");
+  assert.equal(progressText({ stage: "finalizing", engine: "copy", message: "Финализация файла" }), "Финализация файла");
+  assert.equal(progressText({ stage: "audio", engine: "cpu" }), "Обработка аудио · CPU");
+  assert.equal(duration(3661), "1:01:01");
+  assert.equal(duration(61), "1:01");
+  assert.equal(bytes(0), "");
+  assert.match(bytes(1048576), /1 МБ/);
+});
+test("saved quality adapts to another video's formats and never upscales", () => {
+  const metadata = { videos: [{ id: "new-4k", height: 2160, fps: 60, codec: "av01" }, { id: "new-720", height: 720, fps: 30, codec: "avc1" }],
+    audios: [{ id: "new-audio", language: "en" }] };
+  const preference = { folder: "D:\\Videos", videoId: "old-format", audioId: "old-audio", quality: { height: 1080, fps: 30, codec: "H.264" }, audioLanguage: "en", codec: "hevc", engine: "nvenc", videoContainer: "mkv" };
+  const result = preferenceOptions(metadata, preference);
+  assert.equal(result.videoId, "new-720"); assert.equal(result.audioId, "new-audio");
+  assert.equal(result.codec, "hevc"); assert.equal(result.container, "mkv"); assert.equal(result.folder, "D:\\Videos");
+  assert.equal(preferenceOptions(metadata, { ...preference, videoId: "best" }).videoId, "best");
+  assert.equal(preferenceOptions(metadata, { ...preference, mode: "audio", audioContainer: "mp3" }).container, "mp3");
+});
+test("fixed extension ID matches the native host allowed origin", () => {
+  const manifest = JSON.parse(fs.readFileSync(new URL("../extension/manifest.json", import.meta.url)));
+  const digest = crypto.createHash("sha256").update(Buffer.from(manifest.key, "base64")).digest().subarray(0, 16).toString("hex");
+  const id = [...digest].map(character => "abcdefghijklmnop"[parseInt(character, 16)]).join("");
+  assert.equal(id, "ndnoeiaecgmjnjneekaeapeecmmjheli");
+  assert.ok(manifest.permissions.includes("nativeMessaging"));
+  assert.ok(!manifest.host_permissions.includes("<all_urls>"));
+});
+test("brief missing speed samples do not flicker, expire and reset between tracks", () => {
+  const sample = { id: "speed", status: "running", stage: "downloading", track: "video", speed: 4.2 * 1048576 };
+  let previous = stabilizeDownloadSpeed(sample, null, 1000);
+  for (const now of [1200, 1600, 2000, 2400]) {
+    previous = stabilizeDownloadSpeed({ ...sample, speed: null }, previous, now);
+    assert.equal(previous.speed, sample.speed);
+    assert.equal(previous.speedUpdatedAt, 1000, 'Missing samples must not extend the lifetime of the last measurement');
+  }
+  assert.equal(stabilizeDownloadSpeed({ ...sample, speed: null }, previous, 2500).speed, null);
+  assert.equal(stabilizeDownloadSpeed({ ...sample, speed: 0 }, previous, 1200).speed, 0);
+  assert.equal(stabilizeDownloadSpeed({ ...sample, track: "audio", speed: null }, previous, 1200).speed, null);
+  assert.equal(stabilizeDownloadSpeed({ ...sample, stage: "merging", speed: "8x" }, previous, 1200).speedUpdatedAt, null);
+});
+test("helper compatibility detects outdated, newer and unidentifiable versions in both directions", () => {
+  assert.equal(checkHelperCompatibility({ version: "1.3.2" }, "1.4.5").compatible, true);
+  assert.equal(checkHelperCompatibility({ bundle: { version: "1.3.2" } }, "1.4.5").compatible, true);
+  assert.equal(checkHelperCompatibility({ version: "1.3.2.0" }, "1.4.5").compatible, true);
+  for (const version of ["1.3.0", "1.2.10", undefined, "unknown"]) {
+    const result = checkHelperCompatibility({ version }, "1.4.5");
+    assert.equal(result.compatible, false);
+    assert.equal(result.update, "helper");
+  }
+  for (const version of ["1.3.3", "1.3.20", "2.0.0"]) {
+    const result = checkHelperCompatibility({ version }, "1.4.5");
+    assert.equal(result.compatible, false);
+    assert.equal(result.update, "extension");
+  }
+  assert.equal(checkHelperCompatibility({ version: "1.3.2" }, "1.4.2").update, "extension");
+  assert.equal(checkHelperCompatibility({ version: "1.3.2", minimumExtensionVersion: "1.4.6" }, "1.4.5").update, "extension");
+});

tests/helper-lifecycle.test.mjs

@@ -0,0 +1,95 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import os from "node:os";
+import { createHash } from "node:crypto";
+import { execFile } from "node:child_process";
+import { promisify } from "node:util";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+import { installedHelperRoot } from "./installed-helper.mjs";
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts = path.join(root, "test-artifacts");
+const installedRoot = await installedHelperRoot();
+await fs.mkdir(artifacts, { recursive: true });
+const profile = await fs.mkdtemp(path.join(os.tmpdir(), "ytdl-lifecycle-test-"));
+const context = await chromium.launchPersistentContext(profile, {
+  headless: true, acceptDownloads: true,
+  executablePath: "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe",
+  ignoreDefaultArgs: ["--disable-extensions"], args: ["--enable-unsafe-extension-debugging"],
+});
+try {
+  const cdp = await context.browser().newBrowserCDPSession();
+  const { id } = await cdp.send("Extensions.loadUnpacked", { path: path.join(root, "extension") });
+  const worker = context.serviceWorkers()[0] || await context.waitForEvent("serviceworker");
+  const page = await context.newPage();
+  await page.goto(`chrome-extension://${id}/downloader.html`);
+  await page.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  await page.locator('#setup[open]').waitFor();
+  await page.locator('#setup-next').click();
+  await page.locator('#setup-next:not([disabled])').waitFor();
+  assert.match(await page.locator('#setup-helper-status').textContent(), /компоненты готовы/);
+  assert.match(await page.locator('#setup-gpu').textContent(), /RTX 5080/);
+  await page.locator('#setup-next').click();
+  assert.ok(await page.locator('#setup-folder').inputValue());
+  await page.locator('#setup-quality').selectOption('1080');
+  await page.locator('#setup-next').click();
+  await page.locator('[data-setup-step="3"]').waitFor({state:'visible'});
+  await page.screenshot({path:path.join(artifacts,'onboarding-native.png'),animations:'disabled'});
+  await page.locator('#setup-next').click();
+  await page.locator('#setup').waitFor({state:'hidden'});
+  const firstRun = await worker.evaluate(() => chrome.storage.local.get(['preferences','onboarding']));
+  assert.equal(firstRun.onboarding.state,'complete'); assert.equal(firstRun.preferences.quality.height,1080);
+  await page.reload();
+  await page.locator('#helper-panel[data-state="running"]').waitFor({timeout:90000});
+  assert.equal(await page.locator('#setup').evaluate(dialog => dialog.open),false);
+  await page.locator("#helper-panel > summary").click();
+  assert.equal(await page.locator('.dependency-row[data-status="installed"]').count(), 5);
+  await context.route("https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest", route => route.fulfill({ contentType: "text/html", body: "<h1>релизов проекта test destination</h1>" }));
+  const releaseTab = page.waitForEvent("popup");
+  await page.locator("#helper-install").click();
+  const popup = await releaseTab;
+  await popup.waitForURL("https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest");
+  assert.equal(await page.locator("#helper-install").getAttribute("download"), null);
+  await popup.close();
+  const installerPath = path.join(artifacts, "YouTubeDL-Helper-Test.exe");
+  await fs.copyFile(path.join(root, "dist/YouTubeDL-Helper-Setup.exe"), installerPath);
+  const downloaded = await fs.readFile(installerPath);
+  assert.equal(downloaded.subarray(0, 2).toString(), "MZ");
+  assert.equal(createHash("sha256").update(downloaded).digest("hex"), createHash("sha256").update(await fs.readFile(path.join(root,"dist/YouTubeDL-Helper-Setup.exe"))).digest("hex"));
+  console.log("Extension opens the external release page; installer comes from the separate release asset.");
+  await page.locator("#helper-remove").click();
+  await page.locator('#helper-panel[data-state="missing"]').waitFor();
+  assert.equal(await page.locator('.dependency-row[data-status="installed"]').count(), 0);
+  await page.locator("#helper-start").click();
+  await page.locator('#helper-panel[data-state="missing"]').waitFor();
+  const deadline = Date.now() + 40000;
+  while (Date.now() < deadline) {
+    try { await fs.access(path.join(installedRoot,"installation.json")); }
+    catch { break; }
+    await new Promise(resolve => setTimeout(resolve, 100));
+  }
+  await assert.rejects(fs.access(path.join(installedRoot,"installation.json")));
+  console.log("Uninstall verified; missing helper cannot report Running.");
+  const installed = await promisify(execFile)("powershell.exe", ["-NoProfile", "-ExecutionPolicy", "Bypass", "-File", path.join(root, "tools/run-installer-test.ps1"), "-InstallerPath", installerPath], { timeout: 600000 });
+  console.log(installed.stdout.trim());
+  await page.locator("#helper-start").click();
+  await page.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  assert.equal(await page.locator('.dependency-row[data-status="installed"]').count(), 5);
+  assert.equal(await page.locator('.dependency-row button').count(), 0);
+  assert.match(await page.locator('#helper-message').textContent(), /Автономный комплект/);
+  assert.match(await page.locator('[data-dependency="python"] .dependency-version').textContent(), /3\.13\./);
+  const restoredRoot = await installedHelperRoot();
+  const restoredMarker = JSON.parse((await fs.readFile(path.join(restoredRoot,'installation.json'),'utf8')).replace(/^\uFEFF/,''));
+  assert.equal(restoredMarker.version,'1.3.0');
+  await fs.access(path.join(restoredRoot,'YouTubeDL-Manager.exe'));
+  assert.equal(path.dirname(path.dirname(path.resolve(restoredMarker.current))),path.resolve(restoredRoot),'Manager, marker and registered runtime must share the same physical installation');
+  if (!await page.locator('#helper-panel').evaluate(panel => panel.open)) await page.locator('#helper-panel > summary').click();
+  await page.locator('.dependencies summary').click();
+  await page.screenshot({ path: path.join(artifacts, "helper-components.png"), animations: "disabled" });
+  await fs.writeFile(path.join(artifacts, "helper-lifecycle.json"), JSON.stringify({ installer: "YouTubeDL-Helper-Setup.exe", externalReleaseLink: "passed", installerSHA256: createHash("sha256").update(downloaded).digest("hex"), firstRun: "passed", firstRunPersistence: "passed", uninstall: "passed", manualStart: "passed", autonomousBundle: "passed" }, null, 2));
+  console.log("Helper lifecycle passed: external release link, scoped uninstall, missing state, offline installation, manual start and bundled components.");
+} finally {
+  await context.close();
+  if (path.dirname(path.resolve(profile)) === path.resolve(os.tmpdir()) && path.basename(profile).startsWith("ytdl-lifecycle-test-")) await fs.rm(profile, { recursive: true, force: true });
+}

tests/helper-reconnect.test.mjs

@@ -0,0 +1,144 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import os from "node:os";
+import { randomBytes } from "node:crypto";
+import { execFile } from "node:child_process";
+import { promisify } from "node:util";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+
+// Real Edge, real ports, and the bundled installer/helper. Only their host name
+// is isolated so testing removal never touches the user's installed helper.
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts = path.join(root, "test-artifacts");
+const build = path.join(root, ".build");
+await fs.mkdir(build, { recursive: true }); await fs.mkdir(artifacts, { recursive: true });
+const work = await fs.mkdtemp(path.join(build, "reconnect-"));
+const extension = path.join(work, "extension"), helper = path.join(work, "helper");
+const name = `com.youtubedl.test_${randomBytes(8).toString("hex")}`;
+const run = promisify(execFile);
+let manifestPath, context;
+const profile = await fs.mkdtemp(path.join(os.tmpdir(), "ytdl-reconnect-test-"));
+const userRegistration = async () => (await run("powershell.exe", ["-NoProfile", "-Command",
+  "(Get-Item -LiteralPath 'Registry::HKEY_CURRENT_USER\\Software\\Microsoft\\Edge\\NativeMessagingHosts\\com.youtubedl.native' -ErrorAction SilentlyContinue).GetValue('')"])).stdout.trim();
+const beforeRegistration = await userRegistration();
+async function register(remove = false) {
+  await run("powershell.exe", ["-NoProfile", "-ExecutionPolicy", "Bypass", "-File", path.join(root, "tests/test-native-registration.ps1"),
+    "-Name", name, "-ManifestPath", manifestPath, ...(remove ? ["-Remove"] : [])]);
+}
+async function install() {
+  const result = await run(path.join(root, "dist/YouTubeDL-Helper-Setup.exe"), ["--silent", "--no-register", "--target-root", helper], { timeout: 180000, windowsHide: true });
+  assert.match(result.stdout, /100%|Готово/);
+  const marker = JSON.parse((await fs.readFile(path.join(helper, "installation.json"), "utf8")).replace(/^\uFEFF/, ""));
+  assert.equal(path.dirname(path.dirname(path.resolve(marker.current))), path.resolve(helper));
+  const commonPath = path.join(marker.current, "host/common.py");
+  await fs.writeFile(commonPath, (await fs.readFile(commonPath, "utf8")).replace('HOST_NAME = "com.youtubedl.native"', `HOST_NAME = "${name}"`));
+  manifestPath = path.join(marker.current, ".runtime/native-host.json");
+  const manifest = JSON.parse((await fs.readFile(manifestPath, "utf8")).replace(/^\uFEFF/, ""));
+  manifest.name = name; await fs.writeFile(manifestPath, JSON.stringify(manifest));
+  await register();
+}
+try {
+  await fs.cp(path.join(root, "extension"), extension, { recursive: true });
+  const sharedPath = path.join(extension, "shared.js");
+  await fs.writeFile(sharedPath, (await fs.readFile(sharedPath, "utf8")).replace('"com.youtubedl.native"', `"${name}"`));
+  context = await chromium.launchPersistentContext(profile, {
+    headless: true, viewport: { width: 520, height: 820 },
+    executablePath: "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe",
+    ignoreDefaultArgs: ["--disable-extensions"], args: ["--enable-unsafe-extension-debugging"],
+  });
+  const cdp = await context.browser().newBrowserCDPSession();
+  const { id } = await cdp.send("Extensions.loadUnpacked", { path: extension });
+  const worker = context.serviceWorkers()[0] || await context.waitForEvent("serviceworker");
+  // Capture real ports to trigger both sides of a disconnect deterministically.
+  await worker.evaluate(() => {
+    globalThis.__testUiPorts = []; globalThis.__testNativePorts = [];
+    chrome.runtime.onConnect.addListener(port => { if (port.name === "ytdl-ui") globalThis.__testUiPorts.push(port); });
+    const original = chrome.runtime.connectNative.bind(chrome.runtime);
+    chrome.runtime.connectNative = (...args) => { const port = original(...args); globalThis.__testNativePorts.push(port); return port; };
+  });
+  const page = await context.newPage(), errors = [];
+  page.on("pageerror", error => errors.push(error.message));
+  await page.addInitScript(() => {
+    window.__testUiPorts = [];
+    const original = chrome.runtime.connect.bind(chrome.runtime);
+    chrome.runtime.connect = (...args) => { const port = original(...args); window.__testUiPorts.push(port); return port; };
+    window.__pageToken = crypto.randomUUID();
+  });
+  await page.goto(`chrome-extension://${id}/downloader.html?theme=dark`);
+  const token = await page.evaluate(() => window.__pageToken);
+  await page.locator('#setup[open]').waitFor(); await page.locator('#setup-next').click();
+  await page.locator('#setup-helper[data-state="missing"]').waitFor();
+  await worker.evaluate(() => globalThis.__testUiPorts.at(-1).disconnect());
+  await page.locator('#setup-helper[data-state="offline"]').waitFor();
+  console.log("Real UI port disconnected while the helper was missing. Installing a private offline bundle.");
+  await install();
+  await page.locator('#setup-check').click();
+  await page.locator('#setup-helper[data-state="running"]').waitFor({ timeout: 90000 });
+  assert.match(await page.locator('#setup-helper-message').textContent(), /5\/5/);
+  // Chrome does not signal onDisconnect to the end that called disconnect().
+  // This reproduces the exact synchronous 'disconnected port object' race.
+  await page.evaluate(() => window.__testUiPorts.at(-1).disconnect());
+  await page.locator('#setup-check').click();
+  await page.locator('#setup-check:not([disabled])').waitFor();
+  assert.equal(await page.locator('#setup-helper').getAttribute('data-state'), 'running');
+  assert.equal(await page.evaluate(() => window.__pageToken), token);
+  await page.screenshot({ path: path.join(artifacts, "helper-reconnect-setup.png") });
+  console.log("Wizard Check passed after installation and both real port-disconnect cases, without page reload.");
+
+  await page.locator('#setup-skip').click();
+  await page.locator('#helper-panel').evaluate(panel => { panel.open = true; });
+  const other = await context.newPage(); other.on('pageerror', error => errors.push(error.message));
+  await other.goto(`chrome-extension://${id}/downloader.html?theme=dark`);
+  await other.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  await worker.evaluate(() => globalThis.__testUiPorts.forEach(port => { try { port.disconnect(); } catch {} }));
+  await page.locator('#helper-panel[data-state="offline"]').waitFor();
+  await page.locator('#helper-start').click();
+  await page.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  await other.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  await page.locator('#helper-remove').click();
+  await page.locator('#helper-panel[data-state="missing"]').waitFor();
+  await other.locator('#helper-panel[data-state="missing"]').waitFor();
+  assert.equal(await page.locator('.dependency-row[data-status="installed"]').count(), 0);
+  await page.screenshot({ path: path.join(artifacts, "helper-reconnect-removed.png") });
+  const deadline = Date.now() + 60000;
+  while (Date.now() < deadline) {
+    try { await fs.access(path.join(helper, 'installation.json')); }
+    catch { break; }
+    await new Promise(resolve => setTimeout(resolve, 250));
+  }
+  await assert.rejects(fs.access(path.join(helper, 'installation.json')));
+  console.log("Start and actual helper removal passed; both open menus report Missing immediately.");
+  await install();
+  await page.locator('#helper-start').click();
+  await page.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  await other.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  // External registration removal and native-port loss must be discovered by polling.
+  await register(true);
+  await worker.evaluate(() => globalThis.__testNativePorts.at(-1).disconnect());
+  await page.locator('#helper-panel[data-state="missing"]').waitFor({ timeout: 25000 });
+  await other.locator('#helper-panel[data-state="missing"]').waitFor({ timeout: 25000 });
+  await register();
+  await page.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  await other.locator('#helper-panel[data-state="running"]').waitFor({ timeout: 90000 });
+  assert.equal(await page.evaluate(() => window.__pageToken), token);
+  assert.equal(await page.locator('.dependency-row[data-status="installed"]').count(), 5);
+  assert.equal(await page.locator('#alert').isVisible(), false);
+  assert.deepEqual(errors, []);
+  assert.equal(await userRegistration(), beforeRegistration);
+  await page.screenshot({ path: path.join(artifacts, "helper-reconnect-ready.png") });
+  await fs.writeFile(path.join(artifacts, "helper-reconnect-result.json"), JSON.stringify({
+    version: JSON.parse(await fs.readFile(path.join(root,'extension/manifest.json'))).version,
+    actualEdge: true, actualInstaller: true, actualNativePorts: true, checkAfterInstall: true,
+    startAfterDisconnect: true, removalUpdatesAllMenus: true, reinstall: true,
+    pollingDetectsExternalChanges: true, noPageReload: true, userRegistrationUnchanged: true,
+  }, null, 2));
+  console.log("Real helper reconnect passed: Check, Start, removal, reinstall, external changes, two open menus, no page reload.");
+} finally {
+  if (context) await context.close();
+  if (manifestPath) await register(true);
+  assert.equal(await userRegistration(), beforeRegistration);
+  if (path.dirname(path.resolve(profile)) === path.resolve(os.tmpdir()) && path.basename(profile).startsWith("ytdl-reconnect-test-")) await fs.rm(profile, { recursive: true, force: true, maxRetries: 20, retryDelay: 200 });
+  if (path.dirname(path.resolve(work)) === path.resolve(build) && path.basename(work).startsWith("reconnect-")) await fs.rm(work, { recursive: true, force: true, maxRetries: 20, retryDelay: 200 });
+}

tests/history-browser.test.mjs

@@ -0,0 +1,106 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts = path.join(root, "test-artifacts");
+await fs.mkdir(artifacts, { recursive: true });
+const profile = await fs.mkdtemp(path.join(os.tmpdir(), "ytdl-history-test-"));
+const context = await chromium.launchPersistentContext(profile, { headless: true, viewport: { width: 1180, height: 900 },
+  executablePath: "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe", reducedMotion: "reduce",
+  ignoreDefaultArgs: ["--disable-extensions"], args: ["--enable-unsafe-extension-debugging"] });
+const errors = [];
+context.on("page", page => page.on("pageerror", error => errors.push(error.message)));
+const videoUrl = "https://www.youtube.com/watch?v=jNQXAC9IVRw";
+const records = {
+  saved: { id: "saved", title: "Subnautica · Путешествие в глубину", kind: "download", status: "complete", stage: "complete", createdAt: 1791620000,
+    url: videoUrl, result: { filename: "Путешествие в глубину.mp4", path: "D:\\Videos\\Путешествие в глубину.mp4", size: 512 * 1048576 } },
+  cancelled: { id: "cancelled", title: "Отменённое скачивание", kind: "download", status: "cancelled", createdAt: 1791610000 },
+  error: { id: "error", title: "Не удалось скачать видео", kind: "download", status: "error", error: "YouTube запросил подтверждение входа. Подключите вход из текущего профиля браузера в настройках.", url: videoUrl, createdAt: 1791630000 },
+  updateError: { id: "update-error", title: "Обновление компонентов", kind: "update", status: "error", error: "Не удалось получить обновление FFmpeg. Проверьте соединение и повторите попытку.", createdAt: 1791600000 },
+  unsafe: { id: "unsafe", title: '<img src=x onerror="alert(1)">', status: "error", url: "https://evil.test/", error: 'Ошибка <script>alert(1)</script>\n' + "Длинное сообщение. ".repeat(30), createdAt: 1791590000 },
+  updateComplete: { id: "update-complete", title: "Обновление компонентов", kind: "update", status: "complete", createdAt: 1791580000 },
+};
+try {
+  const cdp = await context.browser().newBrowserCDPSession();
+  const { id } = await cdp.send("Extensions.loadUnpacked", { path: path.join(root, "extension") });
+  let worker = context.serviceWorkers()[0] || await context.waitForEvent("serviceworker");
+  await worker.evaluate(async jobs => { await chrome.storage.local.set({ jobs, theme: "dark" }); }, records);
+  const reloaded = context.waitForEvent("serviceworker", { predicate: next => next !== worker, timeout: 20000 });
+  await worker.evaluate(() => { setTimeout(() => chrome.runtime.reload(), 50); });
+  worker = await reloaded;
+  const page = await context.newPage();
+  await page.goto(`chrome-extension://${id}/history.html`);
+  await page.locator('#downloads-list [data-job-id="saved"]').waitFor();
+  await page.waitForTimeout(100);
+  assert.equal(await page.locator('#downloads-list .history-entry').count(), 2);
+  assert.equal(await page.locator('#downloads-count').textContent(), "2");
+  assert.equal(await page.locator('#errors-count').textContent(), "3");
+  assert.match(await page.locator('[data-job-id="saved"] .entry-meta').textContent(), /512 МБ/);
+  assert.match(await page.locator('[data-job-id="saved"] .entry-path').textContent(), /D:\\Videos/);
+  assert.equal(await page.locator('[data-job-id="saved"] a').getAttribute("href"), videoUrl);
+  assert.equal(await page.locator('#errors-panel').isVisible(), false);
+  assert.equal(await page.locator('#history-connection').isVisible(), false, "The real history port must be accepted by the service worker");
+  await page.screenshot({ path: path.join(artifacts, "history-downloads-dark.png") });
+  await page.locator('#errors-tab').click();
+  assert.equal(await page.locator('#downloads-panel').isVisible(), false);
+  assert.equal(await page.locator('#errors-list .history-entry').count(), 3);
+  assert.equal(await page.locator('[data-job-id="unsafe"] img, [data-job-id="unsafe"] script, [data-job-id="unsafe"] a').count(), 0, "Titles/errors are text, and unsafe URLs have no link");
+  await page.screenshot({ path: path.join(artifacts, "history-errors-dark.png") });
+  await page.locator('#errors-tab').press('ArrowLeft');
+  assert.equal(await page.locator('#downloads-tab').getAttribute('aria-selected'), "true");
+  assert.equal(await page.locator('#downloads-tab').evaluate(node => node === document.activeElement), true);
+  // An actual extension UI port must create an actual browser tab.
+  const [opened] = await Promise.all([context.waitForEvent("page"), page.evaluate(async () => {
+    const { createUiConnection } = await import(chrome.runtime.getURL("ui-connection.js"));
+    const { call } = createUiConnection({}); await call("open_history", { theme: "dark" });
+  })]);
+  await opened.waitForURL(`chrome-extension://${id}/history.html?theme=dark`);
+  await opened.locator('#downloads-list .history-entry').first().waitFor();
+  await opened.close();
+  await page.setViewportSize({ width: 360, height: 800 });
+  await page.locator('#theme').click(); // dark -> auto
+  await page.locator('#theme').click(); // auto -> light
+  assert.equal(await page.locator('html').getAttribute('data-theme'), "light");
+  await page.locator('#errors-tab').click();
+  assert.equal(await page.locator('html').evaluate(node => node.scrollWidth > node.clientWidth), false, "History and long errors must fit a narrow viewport");
+  await page.screenshot({ path: path.join(artifacts, "history-errors-light-360.png"), fullPage: true });
+  await page.reload();
+  assert.equal(await page.locator('html').getAttribute('data-theme'), "light");
+  await page.locator('#downloads-list [data-job-id="saved"]').waitFor();
+  assert.equal(await page.locator('#downloads-count').textContent(), "2", "Stored records survive page reload");
+
+  // Browser fixture covers arriving terminal events without starting a real download.
+  await context.route("https://ui.ytdl.test/**", async route => {
+    const name = new URL(route.request().url()).pathname.slice(1);
+    if (!["history.html", "history.js", "history.css", "styles.css", "theme-init.js", "shared.js", "ui-connection.js"].includes(name)) return route.abort();
+    await route.fulfill({ body: await fs.readFile(path.join(root, "extension", name)), contentType: name.endsWith(".html") ? "text/html" : name.endsWith(".css") ? "text/css" : "application/javascript" });
+  });
+  const fixture = await context.newPage();
+  await fixture.addInitScript({ path: path.join(root, "tests/ui-fixture.js") });
+  await fixture.goto("https://ui.ytdl.test/history.html");
+  await fixture.locator('#downloads-empty').waitFor();
+  await fixture.evaluate(records => { window.__emitJob(records.saved); }, records);
+  await fixture.locator('#downloads-list [data-job-id="saved"]').waitFor();
+  await fixture.locator('#errors-tab').click();
+  await fixture.evaluate(records => { window.__emitJob(records.error); }, records);
+  await fixture.locator('#errors-list [data-job-id="error"]').waitFor();
+  assert.equal(await fixture.locator('#errors-tab').getAttribute('aria-selected'), "true", "New records must preserve the chosen tab");
+  await fixture.evaluate(() => window.__emitJob({ id: "active", kind: "download", status: "running", stage: "downloading", createdAt: 1791650000 }));
+  assert.equal(await fixture.locator('#downloads-count').textContent(), "1");
+  assert.equal(await fixture.locator('#errors-count').textContent(), "1");
+  await fixture.evaluate(records => {
+    window.__uiDisconnect();
+    window.__fixtureStorage.jobs[records.updateError.id] = records.updateError;
+  }, records);
+  await fixture.waitForFunction(() => document.getElementById('errors-count').textContent === "2");
+  assert.equal(await fixture.locator('#history-connection').isVisible(), false, "History reconnects and re-reads local records without reload");
+  assert.deepEqual(errors, []);
+  console.log("History passed in actual Edge extension: persistent records, separate tabs, real new-tab action, safe text, themes, keyboard, 360px layout and live completion/error updates.");
+} finally {
+  await context.close();
+  if (path.dirname(path.resolve(profile)) === path.resolve(os.tmpdir()) && path.basename(profile).startsWith("ytdl-history-test-")) await fs.rm(profile, { recursive: true, force: true });
+}

tests/history.test.mjs

@@ -0,0 +1,59 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+test("history connects without a helper, opens a tab, and retains failures before download starts", async () => {
+  const url = "https://www.youtube.com/watch?v=jNQXAC9IVRw";
+  const storage = { jobs: {
+    saved: { id: "saved", title: "Сохранённое видео", kind: "download", status: "complete", result: { path: "D:/Videos/saved.mp4" }, createdAt: 1 },
+    interrupted: { id: "interrupted", status: "running", createdAt: 2 },
+  } };
+  const listeners = {}, tabs = [], nativeRequests = [];
+  const noEvent = { addListener() {} };
+  const runtime = { id: "history-test", getManifest: () => ({ version: "1.4.5" }), getURL: file => `chrome-extension://history-test/${file}`,
+    onConnect: { addListener: listener => { listeners.connect = listener; } }, onMessage: noEvent,
+    connectNative() {
+      let receive;
+      return { onMessage: { addListener: listener => { receive = listener; } }, onDisconnect: noEvent, disconnect() {},
+        postMessage(message) {
+          nativeRequests.push(message);
+          queueMicrotask(() => receive({ id: message.id, ok: message.action !== "inspect", result: message.action === "hello" ? { version: "1.3.2" } : { alive: true }, error: "Видео недоступно" }));
+        } };
+    } };
+  globalThis.chrome = { runtime, storage: { local: { get: async () => structuredClone(storage), set: async data => Object.assign(storage, structuredClone(data)) } },
+    tabs: { create: async tab => { tabs.push(tab); }, sendMessage: async () => {} },
+    notifications: { clear: async () => {}, create: async () => {}, update: async () => true, onButtonClicked: noEvent },
+    permissions: { contains: async () => false },
+    action: { onClicked: noEvent, setBadgeText() {}, setBadgeBackgroundColor() {} },
+  };
+  await import("../extension/background.js?history-test");
+  const attach = file => {
+    let send;
+    const events = [], pending = new Map();
+    listeners.connect({ name: "ytdl-ui", sender: { id: runtime.id, url: runtime.getURL(file) }, onDisconnect: noEvent,
+      onMessage: { addListener: listener => { send = listener; } },
+      postMessage(message) {
+        if (message.id) { pending.get(message.id)?.(message); pending.delete(message.id); }
+        else events.push(message);
+      } });
+    return { connected: () => Boolean(send), events, call: (action, payload = {}) => new Promise(resolve => {
+      const id = crypto.randomUUID(); pending.set(id, resolve); send({ id, action, payload });
+    }) };
+  };
+  const history = attach("history.html?theme=dark"), menu = attach("downloader.html?embedded=1");
+  assert.ok(history.connected());
+  assert.ok(!attach("history.html.evil").connected());
+  assert.ok(!attach("content.js").connected());
+  const state = (await history.call("state")).result;
+  assert.equal(state.jobs.length, 2);
+  assert.equal(state.jobs.find(job => job.id === "interrupted").status, "error");
+  assert.equal(nativeRequests.length, 0, "Viewing history must not launch or query the helper");
+  assert.deepEqual((await menu.call("open_history", { theme: "dark" })).result, { opened: true });
+  assert.deepEqual(tabs, [{ url: runtime.getURL("history.html?theme=dark") }]);
+  const inspection = await menu.call("inspect", { url });
+  assert.equal(inspection.ok, false);
+  assert.equal(inspection.error, "Видео недоступно");
+  const failure = Object.values(storage.jobs).find(job => job.kind === "inspection");
+  assert.equal(failure.error, "Видео недоступно"); assert.equal(failure.url, url);
+  assert.ok(history.events.some(message => message.job?.id === failure.id), "Already open history receives failures immediately");
+  assert.ok(!JSON.stringify(storage).includes("browserCookies"));
+});

tests/installed-helper.mjs

@@ -0,0 +1,23 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import { execFile } from "node:child_process";
+import { promisify } from "node:util";
+import { HOST_NAME } from "../extension/shared.js";
+
+export async function installedHelperRoot() {
+  if (process.env.YTDL_INSTALLED_ROOT) return process.env.YTDL_INSTALLED_ROOT;
+  // A packaged parent process can redirect AppData. Use the registration that
+  // Edge actually opens, rather than a potentially stale LOCALAPPDATA directory.
+  assert.match(HOST_NAME, /^[a-z.]+$/);
+  const command = `$ErrorActionPreference='Stop'; [Console]::OutputEncoding=[Text.UTF8Encoding]::new($false); (Get-Item -LiteralPath 'Registry::HKEY_CURRENT_USER\\Software\\Microsoft\\Edge\\NativeMessagingHosts\\${HOST_NAME}').GetValue('')`;
+  const registration = (await promisify(execFile)("powershell.exe", ["-NoProfile", "-Command", command])).stdout.trim();
+  const native = JSON.parse((await fs.readFile(registration, "utf8")).replace(/^\uFEFF/, ""));
+  assert.equal(native.name, HOST_NAME);
+  const release = path.dirname(path.dirname(native.path));
+  const bundle = JSON.parse(await fs.readFile(path.join(release, "bundle.json"), "utf8"));
+  assert.equal(bundle.product, "YouTubeDL.Helper");
+  assert.equal(bundle.mode, "autonomous");
+  assert.equal(path.basename(path.dirname(release)), "releases");
+  return path.dirname(path.dirname(release));
+}

tests/integration.py

@@ -0,0 +1,166 @@
+"""Real FFmpeg + native messaging checks. Add --online for a small public YouTube download."""
+from __future__ import annotations
+
+import argparse
+import contextlib
+import io
+import json
+import queue
+import subprocess
+import sys
+import threading
+import time
+import uuid
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(ROOT))
+from host.common import EXTENSION_ID
+from host.media import NO_WINDOW, capabilities, config, probe, tool
+from host.protocol import read_message, write_message
+from host.worker import convert
+
+
+class NativeSession:
+    def __init__(self):
+        launcher = ROOT / ".runtime" / "launch-host.cmd"
+        self.process = subprocess.Popen([str(launcher), f"chrome-extension://{EXTENSION_ID}/"],
+                                        stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                                        creationflags=NO_WINDOW)
+        self.messages = queue.Queue()
+        self.jobs = {}
+        self.errors = []
+        def read():
+            try:
+                while (message := read_message(self.process.stdout)) is not None:
+                    self.messages.put(message)
+            except Exception as error:
+                self.messages.put({"protocolError": str(error)})
+        threading.Thread(target=read, daemon=True).start()
+        threading.Thread(target=lambda: self.errors.append(self.process.stderr.read().decode("utf-8", "replace")), daemon=True).start()
+
+    def send(self, action, payload=None):
+        token = str(uuid.uuid4())
+        write_message(self.process.stdin, {"id": token, "action": action, "payload": payload or {}})
+        return token
+
+    def next(self, timeout=150):
+        message = self.messages.get(timeout=timeout)
+        if "protocolError" in message:
+            raise AssertionError(message)
+        if message.get("event") == "job":
+            self.jobs[message["job"]["id"]] = message["job"]
+        return message
+
+    def call(self, action, payload=None):
+        token = self.send(action, payload)
+        while True:
+            message = self.next()
+            if message.get("id") == token:
+                if not message["ok"]:
+                    raise AssertionError(message["error"])
+                return message["result"]
+
+    def download(self, payload):
+        result = self.call("download", payload)
+        job_id = result["jobId"]
+        stage = None
+        deadline = time.monotonic() + 240
+        while time.monotonic() < deadline:
+            job = self.jobs.get(job_id, {})
+            if job.get("status") == "complete": return job["result"]
+            if job.get("status") in {"error", "cancelled"}: raise AssertionError(job)
+            self.next()
+            job = self.jobs.get(job_id, {})
+            if job.get("stage") != stage:
+                stage = job.get("stage"); print(f"Native job: {stage}", flush=True)
+        raise TimeoutError("Native job timeout")
+
+    def close(self):
+        self.process.stdin.close()
+        self.process.wait(timeout=30)
+        if self.process.returncode:
+            raise AssertionError("Native host exit: " + "".join(self.errors))
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--online", action="store_true")
+    args = parser.parse_args()
+    artifacts = ROOT / "test-artifacts"
+    artifacts.mkdir(exist_ok=True)
+    media_dir = artifacts / "media"
+    media_dir.mkdir(exist_ok=True)
+    hardware = capabilities()
+    synthetic = media_dir / "input-vp9-opus.webm"
+    subprocess.run([tool("ffmpeg"), "-hide_banner", "-loglevel", "error", "-y", "-f", "lavfi", "-i", "testsrc2=s=640x360:r=30",
+                    "-f", "lavfi", "-i", "sine=frequency=440:sample_rate=48000", "-t", "0.6", "-c:v", "libvpx-vp9",
+                    "-cpu-used", "8", "-c:a", "libopus", str(synthetic)], check=True, creationflags=NO_WINDOW)
+    summary = {"gpu": hardware["gpu"], "nvenc": hardware["nvenc"], "formats": [], "native": {}}
+    defaults = {"mode": "video", "container": "mp4", "codec": "h264", "engine": "nvenc", "preset": "balanced", "bitrate": 256}
+    source_probe = probe(synthetic)
+    for codec in ("h264", "hevc", "av1"):
+        target = media_dir / f"gpu-{codec}.mp4"
+        with contextlib.redirect_stdout(io.StringIO()):
+            plan = convert(synthetic, target, {**defaults, "codec": codec}, source_probe, hardware["nvenc"])
+        streams = probe(target)["streams"]
+        assert plan["engine"] == "nvenc"
+        assert {s["codec_type"] for s in streams} >= {"video", "audio"}
+        assert next(s for s in streams if s["codec_type"] == "video")["codec_name"] == codec
+        summary["formats"].append({"format": codec, "engine": plan["engine"], "size": target.stat().st_size})
+    for container in ("m4a", "mp3", "opus", "flac", "wav"):
+        target = media_dir / f"audio.{container}"
+        with contextlib.redirect_stdout(io.StringIO()):
+            convert(synthetic, target, {**defaults, "mode": "audio", "container": container}, source_probe, hardware["nvenc"])
+        assert {s["codec_type"] for s in probe(target)["streams"]} == {"audio"}
+        summary["formats"].append({"format": container, "size": target.stat().st_size})
+    target = media_dir / "video-only.mkv"
+    with contextlib.redirect_stdout(io.StringIO()):
+        plan = convert(synthetic, target, {**defaults, "mode": "video_only", "container": "mkv", "codec": "auto"}, source_probe, hardware["nvenc"])
+    assert plan["engine"] == "copy"
+    assert {s["codec_type"] for s in probe(target)["streams"]} == {"video"}
+    with_session = NativeSession()
+    try:
+        hello = with_session.call("hello")
+        summary["native"]["hello"] = hello["gpu"]
+        if args.online:
+            url = "https://www.youtube.com/watch?v=jNQXAC9IVRw"
+            info = with_session.call("inspect", {"url": url})
+            (artifacts / "sample-metadata.json").write_text(json.dumps(info, ensure_ascii=False, indent=2), encoding="utf-8")
+            separated = [f for f in info["videos"] if not f["hasAudio"]]
+            assert separated and info["audios"], "Separate tracks required for this check"
+            chosen = sorted(separated, key=lambda f: (f["height"], f["fps"]))[0]
+            payload = {**defaults, "url": url, "folder": str(media_dir), "videoId": chosen["id"], "audioId": "best", "filename": "YouTube-test-HEVC", "codec": "hevc"}
+            result = with_session.download(payload)
+            downloaded = probe(result["path"])
+            assert {s["codec_type"] for s in downloaded["streams"]} >= {"video", "audio"}
+            assert result["engine"] == "nvenc"
+            summary["native"]["videoPlusAudio"] = result
+            result = with_session.download({**payload, "mode": "audio", "container": "mp3", "filename": "YouTube-test-audio"})
+            assert {s["codec_type"] for s in probe(result["path"])["streams"]} == {"audio"}
+            summary["native"]["audioOnly"] = result
+            result = with_session.download({**payload, "mode": "video_only", "container": "mkv", "codec": "copy", "filename": "YouTube-test-video-only"})
+            assert {s["codec_type"] for s in probe(result["path"])["streams"]} == {"video"}
+            summary["native"]["videoOnly"] = result
+            long_url = "https://www.youtube.com/watch?v=aircAruvnKk"
+            cancel_payload = {**payload, "url": long_url, "videoId": "best", "filename": "cancelled-test"}
+            job_id = with_session.call("download", cancel_payload)["jobId"]
+            while True:
+                message = with_session.next()
+                job = with_session.jobs.get(job_id, {})
+                if job.get("stage") == "downloading": break
+                if job.get("status") == "error": raise AssertionError(job)
+            with_session.call("cancel", {"jobId": job_id})
+            deadline = time.monotonic() + 8
+            while time.monotonic() < deadline and list(media_dir.glob(".ytdl-*")):
+                time.sleep(0.1)
+            assert not list(media_dir.glob(".ytdl-*")), "Cancelled job left temporary files"
+            assert not list(media_dir.glob("cancelled-test.*")), "Cancelled file was published"
+            summary["native"]["cancel"] = "passed; process tree and temporary files removed"
+    finally:
+        with_session.close()
+    (artifacts / "verification.json").write_text(json.dumps(summary, ensure_ascii=False, indent=2), encoding="utf-8")
+    print("Integration checks passed.", flush=True)
+
+
+if __name__ == "__main__": main()

tests/live-shorts.test.mjs

@@ -0,0 +1,89 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs/promises';
+import path from 'node:path';
+import os from 'node:os';
+import { fileURLToPath } from 'node:url';
+import { chromium } from 'playwright';
+
+// This test loads the real YouTube website. No routes or page fixtures.
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts = path.join(root, 'test-artifacts');
+await fs.mkdir(artifacts,{recursive:true});
+const profile = await fs.mkdtemp(path.join(os.tmpdir(),'ytdl-live-shorts-'));
+const context = await chromium.launchPersistentContext(profile,{
+  headless:true, viewport:{width:2160,height:1100},
+  executablePath:'C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe',
+  ignoreDefaultArgs:['--disable-extensions'], args:['--enable-unsafe-extension-debugging','--mute-audio'],
+});
+const cards = 'ytm-shorts-lockup-view-model, yt-shorts-lockup-view-model, ytd-reel-item-renderer';
+try {
+  const cdp = await context.browser().newBrowserCDPSession();
+  const {id} = await cdp.send('Extensions.loadUnpacked',{path:path.join(root,'extension')});
+  const worker = context.serviceWorkers()[0] || await context.waitForEvent('serviceworker');
+  await worker.evaluate(() => chrome.storage.local.set({onboarding:{state:'complete',version:1}}));
+  const page = await context.newPage();
+  const errors=[]; page.on('pageerror',error => errors.push(error.message));
+  console.log('Loading real YouTube search in Edge with the actual extension.');
+  await page.goto(process.env.YTDL_LIVE_URL || 'https://www.youtube.com/results?search_query=subnautica+shorts',{waitUntil:'domcontentloaded',timeout:60000});
+  console.log('YouTube document loaded:',page.url());
+  const consent=page.getByRole('button',{name:/Reject all|Отклонить все/i}).first();
+  if(await consent.isVisible()) await consent.click();
+  await page.locator(cards).first().waitFor({timeout:60000});
+  const first=page.locator(cards).first(); await first.scrollIntoViewIfNeeded();
+  await page.waitForTimeout(1000);
+  const snapshot=()=>page.evaluate(selector => {
+    const box=node=>node ? {...node.getBoundingClientRect().toJSON()} : null;
+    const inspect=node=>({tag:node.tagName,class:node.className,display:getComputedStyle(node).display,
+      overflowX:getComputedStyle(node).overflowX,overflowY:getComputedStyle(node).overflowY,rect:box(node),offsetWidth:node.offsetWidth});
+    return {url:location.href,viewport:{width:innerWidth,height:innerHeight},cards:[...document.querySelectorAll(selector)].slice(0,6).map(card=>{
+      const host=document.querySelector(`[data-ytdl-preview-for="${card.dataset.ytdlPreview}"]`);
+      let ancestors=[];for(let element=card; element;element=element.parentElement)ancestors.push(inspect(element));
+      return {html:card.outerHTML.slice(0,16000),media:[...card.querySelectorAll('img,video')].map(inspect),ancestors,control:host ? {style:host.getAttribute('style'),rect:box(host),buttons:[...host.shadowRoot.querySelectorAll('button')].map(inspect)} : null};
+    }),videos:[...document.querySelectorAll('video')].map(video=>({time:video.currentTime,paused:video.paused,rect:box(video)}))};
+  },cards);
+  const before=await snapshot();
+  await fs.writeFile(path.join(artifacts,'live-shorts-before.json'),JSON.stringify(before,null,2));
+  await page.screenshot({path:path.join(artifacts,'live-shorts-before.png')});
+  console.log('Actual Shorts cards:',before.cards.length,'Controls:',before.cards.map(card=>card.control?.style || 'missing'));
+  if(process.env.YTDL_LIVE_DIAGNOSTIC==='1') {
+    console.log('Live DOM diagnostics saved.');
+  } else {
+    const key=await first.getAttribute('data-ytdl-preview');
+    assert.ok(key,'Real Shorts card must have extension controls');
+    const host=page.locator(`[data-ytdl-preview-for="${key}"]`);
+    await host.locator('.download').waitFor({state:'visible',timeout:15000});
+    const thumbnail=first.locator('a').filter({has:first.locator('img')}).first();
+    const target=await thumbnail.count() ? thumbnail : first;
+    await target.hover();
+    await page.waitForFunction(() => [...document.querySelectorAll('video')].some(video =>
+      !video.paused && video.currentTime > 1 && video.getBoundingClientRect().width > 0),{},{timeout:20000});
+    const after=await snapshot();
+    await fs.writeFile(path.join(artifacts,'live-shorts-hover.json'),JSON.stringify(after,null,2));
+    await page.screenshot({path:path.join(artifacts,'live-shorts-hover.png')});
+    const shelf=first.locator('xpath=ancestor::*[self::grid-shelf-view-model or self::ytd-rich-shelf-renderer or self::ytd-reel-shelf-renderer][1]');
+    if(await shelf.count()) await shelf.screenshot({path:path.join(artifacts,'live-shorts-proof.png')});
+    assert.ok(after.videos.some(video=>!video.paused && video.time>1 && video.rect.width>0),'Real YouTube preview video must actually play');
+    await host.locator('.download').waitFor({state:'visible'});
+    assert.equal(await host.locator('.settings').isVisible(),true);
+    const hit=await host.evaluate(node=>{const r=node.getBoundingClientRect();return document.elementFromPoint(r.left+17,r.top+17)===node;});
+    assert.equal(hit,true,'Real hover player must not cover the download button');
+    await host.locator('.settings').click();
+    await page.locator('#ytdl-menu iframe').waitFor({state:'visible'});
+    const menu=page.frameLocator('#ytdl-menu iframe');
+    await menu.locator('#helper-panel:not([data-state="checking"]):not([data-state="idle"])').waitFor({timeout:90000});
+    const helperStatus=await menu.locator('#helper-panel').getAttribute('data-state');
+    if(helperStatus==='running') assert.equal(await menu.locator('.dependency-row[data-status="installed"]').count(),5);
+    else assert.equal(await menu.locator('.dependency-row[data-status="installed"]').count(),0,'Unavailable helper must not retain ready component indicators');
+    assert.ok(!/disconnected port object/i.test(await menu.locator('#helper-message').textContent()));
+    console.log('Embedded menu actual helper state:',helperStatus,await menu.locator('#helper-message').textContent());
+    await fs.writeFile(path.join(artifacts,'live-shorts-result.json'),JSON.stringify({
+      url:page.url(),extensionId:id,version:JSON.parse(await fs.readFile(path.join(root,'extension','manifest.json'))).version,
+      actualPreviewPlaying:true,controlsVisible:true,downloadHitTest:true,settingsOpened:true,embeddedConnectionModuleLoaded:true,embeddedHelperStatus:helperStatus,
+    },null,2));
+    console.log('Live Shorts passed: actual preview playback, visible controls before/after hover, hit testing, settings click and actual helper state in the embedded menu.');
+  }
+  await fs.writeFile(path.join(artifacts,'live-shorts-errors.json'),JSON.stringify(errors,null,2));
+} finally {
+  await context.close();
+  if(path.dirname(path.resolve(profile))===path.resolve(os.tmpdir()) && path.basename(profile).startsWith('ytdl-live-shorts-')) await fs.rm(profile,{recursive:true,force:true});
+}

tests/native-connection.test.mjs

@@ -0,0 +1,112 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+test("native lifecycle recovers stale ports and publishes install/remove/update state to all menus", async () => {
+  const ports = [], listeners = {}, storage = {}, pending = new Map(), updates = [];
+  let installed = false;
+  let helperVersion = "1.3.2";
+  let componentsReady = true;
+  const noEvent = { addListener() {} };
+  const runtime = { id: "test-id", getManifest: () => ({ version: "1.4.5" }), getURL: name => `chrome-extension://test-id/${name}`,
+    onConnect: { addListener: listener => { listeners.connect = listener; } }, onMessage: noEvent,
+    connectNative() {
+      let receive, disconnected;
+      const port = { sent: [], dead: false,
+        onMessage: { addListener: listener => { receive = listener; } },
+        onDisconnect: { addListener: listener => { disconnected = listener; } },
+        disconnect() { this.dead = true; queueMicrotask(() => disconnected()); },
+        emit: message => receive(message),
+        postMessage(message) {
+          if (this.dead) throw new Error("Attempting to use a disconnected port object");
+          this.sent.push(message);
+          if (!installed) {
+            queueMicrotask(() => { this.dead = true; runtime.lastError = { message: "Specified native messaging host not found." }; disconnected(); delete runtime.lastError; });
+            return;
+          }
+          const result = message.action === "hello" ? { version: helperVersion, ready: componentsReady, gpu: "Test GPU" }
+            : message.action === "ping" ? { alive: true }
+            : message.action === "helper_uninstall" ? { removed: true }
+            : message.action === "helper_update" ? { jobId: "update-job" } : {};
+          if (message.action === "helper_uninstall") installed = false;
+          queueMicrotask(() => receive({ id: message.id, ok: true, result }));
+        },
+      };
+      ports.push(port); return port;
+    },
+  };
+  globalThis.chrome = { runtime,
+    storage: { local: { get: async () => storage, set: async values => Object.assign(storage, values) } },
+    notifications: { clear: async () => {}, create: async () => {}, update: async () => true, onButtonClicked: noEvent },
+    tabs: { sendMessage: async () => {} },
+    action: { onClicked: noEvent, setBadgeText() {}, setBadgeBackgroundColor() {} },
+  };
+  await import("../extension/background.js?native-lifecycle-test");
+  let send;
+  const attach = collect => listeners.connect({ name: "ytdl-ui", sender: { id: runtime.id, url: runtime.getURL("downloader.html") },
+    onDisconnect: noEvent, onMessage: { addListener: listener => { send = listener; } },
+    postMessage(message) {
+      if (message.id) { pending.get(message.id)?.(message); pending.delete(message.id); }
+      else collect.push(message);
+    },
+  });
+  const otherMenu = []; attach(otherMenu); attach(updates);
+  const call = (action, payload = {}) => new Promise(resolve => {
+    const id = crypto.randomUUID(); pending.set(id, resolve); send({ id, action, payload });
+  });
+  assert.equal((await call("helper_start")).ok, false);
+  assert.equal(updates.at(-1).helper.status, "missing");
+  installed = true;
+  assert.equal((await call("helper_status")).result.status, "running", "Polling discovers a newly installed helper");
+  ports.at(-1).dead = true;
+  assert.equal((await call("helper_start")).ok, true, "One click must recover a stale native port before its disconnect callback");
+  const fresh = ports.at(-1);
+  const speedJob = { id: "speed-dropout", status: "running", stage: "downloading", track: "video", speed: 4.2 * 1048576 };
+  fresh.emit({ event: "job", job: speedJob });
+  await new Promise(resolve => setImmediate(resolve));
+  fresh.emit({ event: "job", job: { ...speedJob, speed: null } });
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(updates.filter(message => message.job?.id === speedJob.id).at(-1).job.speed, speedJob.speed, "Native progress normalizes a missing speed before publishing to menus and notifications");
+  fresh.emit({ event: "job", job: { ...speedJob, track: "audio", speed: null } });
+  await new Promise(resolve => setImmediate(resolve));
+  assert.equal(updates.filter(message => message.job?.id === speedJob.id).at(-1).job.speed, null, "A new audio track must not inherit the video's speed");
+  fresh.emit({ event: "job", job: { ...speedJob, status: "cancelled", stage: "cancelled", speed: null } });
+  await new Promise(resolve => setImmediate(resolve));
+  ports.at(-2).disconnect(); await new Promise(resolve => setImmediate(resolve));
+  assert.equal((await call("helper_status")).result.status, "running", "Old disconnect must not invalidate the replacement");
+  assert.equal((await call("helper_remove")).ok, true);
+  assert.equal(updates.at(-1).helper.status, "missing");
+  assert.equal(otherMenu.at(-1).helper.status, "missing", "Removal updates every open menu");
+  assert.equal((await call("helper_status")).result.status, "missing");
+  installed = true;
+  assert.equal((await call("helper_start")).ok, true);
+  await call("helper_update", { title: "Обновление компонентов" });
+  const updatingPort = ports.at(-1);
+  updatingPort.emit({ event: "job", job: { id: "update-job", kind: "update", status: "complete", stage: "complete", result: { restartRequired: true } } });
+  await new Promise(resolve => setTimeout(resolve, 20));
+  assert.notEqual(ports.at(-1), updatingPort);
+  assert.equal((await call("helper_status")).result.status, "running", "Component update reconnects and republishes measured capabilities");
+  componentsReady = false;
+  ports.at(-1).emit({ event: "job", job: { id: "broken-component", kind: "dependency", status: "error", stage: "error", error: "Компонент недоступен" } });
+  await new Promise(resolve => setTimeout(resolve, 20));
+  assert.equal((await call("state")).result.helper.hardware.ready, false, "A failed component operation refreshes readiness");
+  componentsReady = true;
+  ports.at(-1).emit({ event: "job", job: { id: "restored-component", kind: "dependency", status: "complete", stage: "complete" } });
+  await new Promise(resolve => setTimeout(resolve, 20));
+  assert.equal((await call("state")).result.helper.hardware.ready, true, "Restoring a component refreshes readiness without reload");
+  assert.ok(fresh.sent.some(message => message.action === "helper_uninstall"));
+  for (const [version, update] of [["1.3.0", "helper"], ["1.3.3", "extension"]]) {
+    helperVersion = version;
+    ports.at(-1).disconnect();
+    await new Promise(resolve => setImmediate(resolve));
+    assert.equal((await call("helper_start")).ok, false);
+    const state = (await call("state")).result.helper;
+    assert.equal(state.status, "incompatible");
+    assert.equal(state.compatibility.update, update);
+    assert.equal(state.hardware.version, version);
+    const port = ports.at(-1);
+    assert.equal((await call("download", { url: "https://youtu.be/jNQXAC9IVRw" })).ok, false, 'Incompatible versions cannot launch a download');
+    assert.ok(!port.sent.some(message => message.action === "download"));
+  }
+  helperVersion = "1.3.2";
+  assert.equal((await call("helper_status")).result.status, "running", 'Version repair is detected by the Check button without reloading');
+});

tests/offline-bundle.py

@@ -0,0 +1,97 @@
+"""Exercise the real offline installer with unusable external tools and proxies."""
+import ctypes
+import json
+import os
+import subprocess
+import tempfile
+import time
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+ARTIFACTS = ROOT / "test-artifacts"
+ARTIFACTS.mkdir(exist_ok=True)
+INSTALLER = ROOT / "dist/YouTubeDL-Helper-Setup.exe"
+environment = {**os.environ, "PATH": str(Path(os.environ.get("SystemRoot", r"C:\Windows")) / "System32"),
+               "PYTHONHOME": "C:/NONEXISTENT", "PYTHONPATH": "C:/NONEXISTENT", "PYTHONNOUSERSITE": "1",
+               "HTTP_PROXY": "http://127.0.0.1:9", "HTTPS_PROXY": "http://127.0.0.1:9", "ALL_PROXY": "http://127.0.0.1:9"}
+
+
+def run(*args):
+    result = subprocess.run([str(item) for item in args], env=environment, capture_output=True,
+                            encoding="utf-8", errors="replace", timeout=180)
+    if result.returncode:
+        raise RuntimeError(json.dumps({"code": result.returncode, "stdout": result.stdout[-500:], "stderr": result.stderr[-2500:]}))
+    return result
+
+
+def picker(manager, folder):
+    import base64
+    encoded = base64.b64encode(json.dumps(str(folder)).encode()).decode()
+    process = subprocess.Popen([str(manager), "--pick-folder", "--initial-folder", encoded], env=environment,
+                               stdout=subprocess.PIPE, stderr=subprocess.PIPE, creationflags=subprocess.CREATE_NO_WINDOW)
+    user32 = ctypes.windll.user32
+    callback_type = ctypes.WINFUNCTYPE(ctypes.c_bool, ctypes.c_void_p, ctypes.c_void_p)
+    dialogs = []
+    def callback(window, unused):
+        pid = ctypes.c_ulong(); user32.GetWindowThreadProcessId(window, ctypes.byref(pid))
+        if pid.value == process.pid:
+            name = ctypes.create_unicode_buffer(256); user32.GetClassNameW(window, name, 256)
+            if name.value == "#32770" and user32.IsWindowVisible(window): dialogs.append(window)
+        return True
+    deadline = time.monotonic() + 15
+    handler = callback_type(callback)
+    while not dialogs and time.monotonic() < deadline:
+        user32.EnumWindows(handler, 0); time.sleep(0.1)
+    assert dialogs, "The bundled Windows folder picker must open"
+    # Select its preselected existing folder, including Unicode in the path.
+    user32.PostMessageW(ctypes.c_void_p(dialogs[0]), 0x0111, 1, 0)  # WM_COMMAND / IDOK
+    output, errors = process.communicate(timeout=15)
+    assert process.returncode == 0, errors.decode("utf-8", errors="replace")
+    assert Path(json.loads(output)) == folder
+
+
+with tempfile.TemporaryDirectory(prefix="offline-bundle-", dir=ARTIFACTS) as temporary:
+    parent = Path(temporary)
+    application = parent / "Helper"
+    legacy = application / ".runtime"; legacy.mkdir(parents=True)
+    (legacy / "completed-jobs.json").write_text("[]")
+    first = run(INSTALLER, "--silent", "--no-register", "--target-root", application)
+    assert (application / "data/completed-jobs.json").read_text() == "[]"
+    marker = json.loads((application / "installation.json").read_text(encoding="utf-8-sig"))
+    release = Path(marker["current"])
+    python = release / "runtime/python/python.exe"
+    measured = json.loads(run(python, "-I", "-B", "-c",
+        "import json,sys; from host.media import capabilities,tool; print(json.dumps({'python':sys.executable,'path':sys.path,'hardware':capabilities(),'tools':{k:tool(k) for k in ('node','ffmpeg','ffprobe')}}))").stdout)
+    assert measured["hardware"]["ready"]
+    assert measured["hardware"]["bundle"]["mode"] == "autonomous"
+    assert {"h264", "hevc", "av1"} <= set(measured["hardware"]["nvenc"]), measured["hardware"]
+    assert Path(measured["python"]).is_relative_to(release)
+    assert all(Path(path).is_relative_to(release) for path in measured["tools"].values())
+    assert all(Path(path).is_relative_to(release) for path in measured["path"])
+    picker(application / "YouTubeDL-Manager.exe", ARTIFACTS)
+    preserved = release / "user-kept.mp4"; preserved.write_bytes(b"user file")
+    history = application / "data/completed-jobs.json"; history.parent.mkdir(exist_ok=True); history.write_text("[]")
+    # Reinstall beside the running copy; an old DLL handle must not prevent repair.
+    handle = (release / "runtime/python/python313.dll").open("rb")
+    try: run(INSTALLER, "--silent", "--no-register", "--target-root", application)
+    finally: handle.close()
+    current = Path(json.loads((application / "installation.json").read_text(encoding="utf-8-sig"))["current"])
+    assert current != release and current.is_dir()
+    manager = application / "YouTubeDL-Manager.exe"
+    run(manager, "--uninstall", "--silent", "--target-root", application)
+    assert preserved.read_bytes() == b"user file" and history.read_text() == "[]"
+    assert not current.exists() and not python.exists()
+    deadline = time.monotonic() + 15
+    while manager.exists() and time.monotonic() < deadline: time.sleep(0.1)
+    assert not manager.exists(), "The uninstaller must remove its own installed executable"
+    # Payload damage must be rejected before registering or installing any tools.
+    damaged = parent / "damaged.exe"
+    payload = bytearray(INSTALLER.read_bytes()); offset = payload.index(b"PK\x03\x04"); payload[offset + 100] ^= 1
+    damaged.write_bytes(payload)
+    invalid = subprocess.run([str(damaged), "--silent", "--no-register", "--target-root", str(parent / "Invalid")],
+                             env=environment, capture_output=True, encoding="utf-8", timeout=60)
+    assert invalid.returncode != 0 and "Контрольная сумма" in invalid.stderr, invalid.stderr
+    (ARTIFACTS / "offline-bundle.json").write_text(json.dumps({"offlineInstallation": "passed", "isolatedRuntime": "passed",
+        "folderPicker": "passed", "repairWhileOldFilesOpen": "passed", "uninstallPreservesUserMedia": "passed", "corruptedPayload": "rejected",
+        "versions": measured["hardware"]["dependencies"], "nvenc": measured["hardware"]["nvenc"]}, ensure_ascii=False, indent=2), encoding="utf-8")
+print("Offline bundle passed: isolated runtime, blocked proxies, Windows picker, NVENC, repair, scoped uninstall and damaged-payload rejection.")

tests/onboarding.test.mjs

@@ -0,0 +1,110 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts = path.join(root, "test-artifacts");
+await fs.mkdir(artifacts, { recursive: true });
+const browser = await chromium.launch({ headless: true, executablePath: "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe" });
+const context = await browser.newContext({ viewport: { width: 520, height: 820 }, reducedMotion: "reduce" });
+await context.addInitScript({ path: path.join(root, "tests/ui-fixture.js") });
+await context.route("https://ui.ytdl.test/**", async route => {
+  const name = new URL(route.request().url()).pathname.slice(1);
+  if (!["downloader.html", "downloader.js", "onboarding.js", "ui-connection.js", "theme-init.js", "styles.css", "shared.js", "session.js"].includes(name)) return route.abort();
+  return route.fulfill({ body: await fs.readFile(path.join(root, "extension", name)), contentType: name.endsWith(".html") ? "text/html" : name.endsWith(".css") ? "text/css" : "application/javascript" });
+});
+const errors = [];
+context.on("page", page => page.on("pageerror", error => errors.push(error.message)));
+try {
+  const page = await context.newPage();
+  await page.addInitScript(() => { window.__firstRun = true; window.__helperMissing = true; });
+  await page.goto("https://ui.ytdl.test/downloader.html?theme=dark");
+  await page.locator("#setup[open]").waitFor();
+  await page.screenshot({ path: path.join(artifacts, "onboarding-welcome.png"), animations: "disabled" });
+  await page.locator("#setup-next").click();
+  await page.locator('#setup-helper[data-state="missing"]').waitFor();
+  assert.equal(await page.locator("#setup-next").isDisabled(), true);
+  assert.equal(await page.locator("#setup-install").isVisible(), true);
+  assert.equal(await page.locator("#setup-install").getAttribute("href"), "https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest");
+  assert.equal(await page.locator("#setup-install").getAttribute("target"), "_blank");
+  assert.equal(await page.locator("#setup-install").getAttribute("download"), null);
+  assert.equal(await page.locator("#setup-install-steps li").count(), 3);
+  await page.screenshot({ path: path.join(artifacts, "onboarding-install.png"), animations: "disabled" });
+  // A connected helper with a broken component is insufficient to continue.
+  await page.evaluate(() => { window.__helperMissing = false; window.__dependencyMissing = true; });
+  await page.locator("#setup-check").click();
+  await page.locator("#setup-check:not([disabled])").waitFor();
+  assert.equal(await page.locator("#setup-next").isDisabled(), true);
+  assert.match(await page.locator("#setup-install").textContent(), /восстановления/);
+  await page.evaluate(() => { window.__dependencyMissing = false; });
+  await page.locator("#setup-check").click();
+  await page.locator("#setup-next:not([disabled])").waitFor();
+  assert.match(await page.locator("#setup-helper-message").textContent(), /5\/5/);
+  assert.match(await page.locator("#setup-gpu").textContent(), /RTX 5080.*NVENC/);
+  await page.locator("#setup-updates").uncheck();
+  await page.locator("#setup-next:not([disabled])").waitFor();
+  assert.equal(await page.locator("#setup-updates").isChecked(), false);
+  await page.locator("#setup-next").click();
+  await page.locator("#setup-folder").fill("");
+  await page.locator("#setup-next").click();
+  assert.match(await page.locator("#setup-error").textContent(), /Выберите папку/);
+  await page.locator("#setup-pick-folder").click();
+  await page.locator("#setup-pick-folder:not([disabled])").waitFor();
+  assert.equal(await page.locator("#setup-folder").inputValue(), "D:\\Videos\\YouTube");
+  await page.locator("#setup-pick-work-folder").click();
+  await page.locator("#setup-pick-work-folder:not([disabled])").waitFor();
+  assert.equal(await page.locator("#setup-work-folder").inputValue(), "D:\\Videos\\YouTube");
+  await page.locator("#setup-work-folder").fill("F:\\Scratch");
+  await page.locator("#setup-mode").selectOption("audio");
+  assert.equal(await page.locator("#setup-quality-field").isVisible(), false);
+  await page.locator("#setup-format").selectOption("mp3");
+  await page.locator("#setup-mode").selectOption("video");
+  await page.locator("#setup-format").selectOption("mkv");
+  await page.locator("#setup-quality").selectOption("1080");
+  await page.screenshot({ path: path.join(artifacts, "onboarding-settings.png"), animations: "disabled" });
+  await page.locator("#setup-next").click();
+  await page.locator('[data-setup-step="3"]').waitFor({ state: "visible" });
+  assert.match(await page.locator("#setup-saved").textContent(), /D:\\Videos\\YouTube/);
+  await page.locator("#setup-next").click();
+  await page.locator("#setup").waitFor({ state: "hidden" });
+  const result = await page.evaluate(() => window.__fixtureStorage);
+  assert.equal(result.onboarding.state, "complete");
+  assert.equal(result.preferences.videoContainer, "mkv");
+  assert.equal(result.preferences.audioContainer, "mp3");
+  assert.equal(result.preferences.quality.height, 1080);
+  assert.equal(result.preferences.workFolder, "F:\\Scratch");
+  assert.equal(result.preferences.engine, "auto");
+  await page.locator("#open-setup").click();
+  await page.locator("#setup[open]").waitFor();
+  await page.keyboard.press("Escape");
+  await page.locator("#setup").waitFor({ state: "hidden" });
+  assert.equal(await page.evaluate(() => window.__fixtureStorage.onboarding.state), "skipped");
+  await page.close();
+
+  const narrow = await context.newPage();
+  await narrow.setViewportSize({ width: 340, height: 560 });
+  await narrow.addInitScript(() => { window.__firstRun = true; });
+  await narrow.goto("https://ui.ytdl.test/downloader.html?theme=light");
+  await narrow.locator("#setup[open]").waitFor();
+  await narrow.locator("#setup-next").click();
+  await narrow.locator("#setup-next:not([disabled])").waitFor();
+  const box = await narrow.locator("#setup").boundingBox();
+  assert.ok(box.x >= 0 && box.x + box.width <= 340 && box.y >= 0 && box.y + box.height <= 560);
+  assert.equal(await narrow.locator("#setup-next").isVisible(), true);
+  await narrow.screenshot({ path: path.join(artifacts, "onboarding-light-narrow.png"), animations: "disabled" });
+  await narrow.locator("#setup-skip").click();
+  await narrow.locator("#setup").waitFor({ state: "hidden" });
+  assert.equal(await narrow.evaluate(() => window.__fixtureStorage.onboarding.state), "skipped");
+  await narrow.close();
+
+  const existing = await context.newPage();
+  await existing.addInitScript(() => { window.__firstRun = true; window.__fixtureStorage.preferences = { folder: "D:\\Existing", videoContainer: "webm" }; });
+  await existing.goto("https://ui.ytdl.test/downloader.html");
+  await existing.locator('#helper-panel[data-state="running"]').waitFor();
+  assert.equal(await existing.locator("#setup").evaluate(dialog => dialog.open), false, "Configured profiles are not interrupted by a new guide");
+  assert.equal(await existing.locator("#folder").inputValue(), "D:\\Existing");
+  assert.deepEqual(errors, []);
+  console.log("Onboarding passed: first launch, missing/broken helper, real-state gating, update toggle, folder validation, video/audio defaults, skip, reopen, Escape, existing profiles and narrow light theme.");
+} finally { await browser.close(); }

tests/progress-motion.test.mjs

@@ -0,0 +1,176 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import os from "node:os";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+
+// Real extension toast on live YouTube, with controlled progress messages.
+// Settings use their real active-job renderer and the existing browser-API fixture.
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts = path.join(root, "test-artifacts");
+await fs.mkdir(artifacts, { recursive: true });
+const profile = await fs.mkdtemp(path.join(os.tmpdir(), "ytdl-motion-test-"));
+const context = await chromium.launchPersistentContext(profile, {
+  headless: true, viewport: { width: 1280, height: 900 }, reducedMotion: "no-preference",
+  executablePath: "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe",
+  ignoreDefaultArgs: ["--disable-extensions"], args: ["--enable-unsafe-extension-debugging", "--mute-audio"],
+});
+try {
+  const cdp = await context.browser().newBrowserCDPSession();
+  await cdp.send("Extensions.loadUnpacked", { path: path.join(root, "extension") });
+  const worker = context.serviceWorkers()[0] || await context.waitForEvent("serviceworker");
+  const page = await context.newPage();
+  await page.goto("https://www.youtube.com/results?search_query=subnautica+shorts", { waitUntil: "domcontentloaded", timeout: 60000 });
+  const consent = page.getByRole("button", { name: /Reject all|Отклонить все/i }).first();
+  if (await consent.isVisible()) await consent.click();
+  await page.waitForTimeout(700);
+  const tabId = await worker.evaluate(async url => (await chrome.tabs.query({})).find(tab => tab.url === url).id, page.url());
+  await context.route("https://ui.ytdl.test/**", async route => {
+    const name = new URL(route.request().url()).pathname.slice(1);
+    if (!["downloader.html", "styles.css", "downloader.js", "onboarding.js", "ui-connection.js", "theme-init.js", "shared.js", "session.js"].includes(name)) return route.abort();
+    await route.fulfill({ body: await fs.readFile(path.join(root, "extension", name)), contentType: name.endsWith(".html") ? "text/html" : name.endsWith(".css") ? "text/css" : "application/javascript" });
+  });
+  const menu = await context.newPage();
+  await menu.addInitScript({ path: path.join(root, "tests/ui-fixture.js") });
+  const errors = []; menu.on("pageerror", error => errors.push(error.message));
+  await menu.goto("https://ui.ytdl.test/downloader.html?theme=dark");
+  await menu.locator('#helper-panel[data-state="running"]').waitFor();
+  const jobId = "motion-preview";
+  const emit = async (values = {}) => {
+    const job = { id: jobId, title: "Проверка анимации прогресса", status: "running", stage: "downloading", track: "video", percent: 25, downloaded: 123.4 * 1048576, total: 850 * 1048576, speed: 41.5 * 1048576, ...values };
+    await worker.evaluate(async ({ tabId, job }) => { await chrome.tabs.sendMessage(tabId, { type: "JOB_PROGRESS", job }).catch(() => {}); }, { tabId, job });
+    await menu.evaluate(job => window.__emitJob(job), job);
+    await page.locator(`#ytdl-notifications [data-id="${jobId}"]`).waitFor();
+  };
+  const toastFill = page.locator(`#ytdl-notifications [data-id="${jobId}"] .fill`);
+  const historyFill = menu.locator(`[data-job-id="${jobId}"] .progress-fill`);
+  const toastTransfer = page.locator(`#ytdl-notifications [data-id="${jobId}"] .transfer`);
+  const historyTransfer = menu.locator(`[data-job-id="${jobId}"] .job-transfer`);
+  async function checkSize(values, expected, expectedHistory = expected) {
+    await emit(values);
+    await page.waitForFunction(({ id, text }) => document.querySelector('#ytdl-notifications').shadowRoot.querySelector(`[data-id="${id}"] .transfer`).textContent === text, { id: jobId, text: expected });
+    for (const [label, text] of [[toastTransfer, expected], ...(values.status && values.status !== "running" ? [] : [[historyTransfer, expectedHistory]])]) {
+      assert.equal(await label.textContent(), text);
+      assert.equal(await label.evaluate(node => node.hidden), !text);
+      if (text) assert.equal(await label.evaluate(node => node.scrollWidth <= node.clientWidth), true, "Byte count must fit without truncation");
+    }
+  }
+  async function sample(fill, indeterminate) {
+    await fill.page().bringToFront();
+    return fill.evaluate(async (node, waiting) => {
+      const frame = () => new Promise(resolve => requestAnimationFrame(() => requestAnimationFrame(resolve)));
+      await frame();
+      void getComputedStyle(node, '::after').animationName;
+      const scope = node.getRootNode();
+      // Chrome exposes pseudo-element animations through the ShadowRoot timeline.
+      const animation = scope.getAnimations().find(item => item.effect?.target === node && item instanceof CSSAnimation);
+      if (!animation) throw new Error("Running progress must actually animate: " + JSON.stringify({
+        node: node.outerHTML, reduced: matchMedia('(prefers-reduced-motion: reduce)').matches,
+        pseudo: { animation: getComputedStyle(node, '::after').animationName, duration:getComputedStyle(node, '::after').animationDuration, content: getComputedStyle(node, '::after').content },
+        animations: node.getAnimations({subtree:true}).map(item => ({name:item.animationName,type:item.constructor.name,css:item instanceof CSSAnimation})),
+        frames: [...(node.getRootNode().querySelector('style')?.sheet?.cssRules || [])].filter(rule=>rule.type===CSSRule.KEYFRAMES_RULE).map(rule=>rule.name),
+        rootAnimations: node.getRootNode().getAnimations?.().map(item=>({name:item.animationName,target:item.effect?.target?.className})),
+        geometry:node.getBoundingClientRect().toJSON(),visibility:document.visibilityState,
+      }));
+      animation.pause();
+      const duration = animation.effect.getTiming().duration;
+      const track = node.parentElement, positions = [];
+      for (const phase of [0, .125, .25, .375, .5, .625, .75, .875, .999]) {
+        animation.currentTime = duration * phase; await frame();
+        const bar = node.getBoundingClientRect(), bounds = track.getBoundingClientRect();
+        if (waiting && (bar.left < bounds.left - .2 || bar.right > bounds.right + .2)) throw new Error("Waiting segment escaped the track");
+        // A pseudo-element painted outside its fill also intercepts this hit test.
+        // Probe the unfilled track, rather than merely checking CSS property names.
+        for (let x = bounds.left + 2; x < bounds.right - 2; x += 2) {
+          if (x >= bar.left - 1 && x <= bar.right + 1) continue;
+          const hit = scope.elementFromPoint(x, bounds.top + bounds.height / 2);
+          if (hit === node) throw new Error("Moving highlight leaked into the unfilled track");
+        }
+        positions.push({ phase, left: bar.left - bounds.left, right: bar.right - bounds.left, trackWidth: bounds.width });
+      }
+      if (waiting) {
+        const travel = Math.max(...positions.map(item => item.left)) - Math.min(...positions.map(item => item.left));
+        if (travel < positions[0].trackWidth * .5) throw new Error("Waiting animation barely moves");
+        for (let i = 1; i < 5; i++) if (positions[i].left < positions[i - 1].left - .2) throw new Error("Waiting motion changes direction too early");
+        for (let i = 5; i < positions.length; i++) if (positions[i].left > positions[i - 1].left + .2) throw new Error("Waiting motion does not return smoothly");
+      }
+      animation.currentTime = duration * (waiting ? .5 : .75); await frame();
+      return positions;
+    }, indeterminate);
+  }
+  const results = [];
+  await emit();
+  await page.waitForTimeout(400);
+  await page.evaluate(id => {
+    const toast = document.querySelector('#ytdl-notifications').shadowRoot.querySelector(`[data-id="${id}"]`);
+    window.__unchangedReadoutMutations = [];
+    window.__readoutObserver = new MutationObserver(records => window.__unchangedReadoutMutations.push(...records.map(record => record.target.parentElement?.className || record.target.className)));
+    for (const selector of ['.title', '.stage', '.icon', '.label', '.action']) window.__readoutObserver.observe(toast.querySelector(selector), { childList: true, characterData: true, subtree: true });
+  }, jobId);
+  await menu.evaluate(() => {
+    window.__cardMoves = 0;
+    window.__cardObserver = new MutationObserver(records => { window.__cardMoves += records.length; });
+    window.__cardObserver.observe(document.querySelector('#active-jobs'), { childList: true });
+  });
+  for (let index = 0; index < 10; index++) await emit({ downloaded: (124 + index) * 1048576 });
+  const unchangedReadoutMutations = await page.evaluate(() => {
+    window.__readoutObserver.disconnect();
+    return window.__unchangedReadoutMutations;
+  });
+  assert.deepEqual(unchangedReadoutMutations, [], 'Unchanged progress labels must not be rebuilt for each byte-count event');
+  assert.equal(await menu.evaluate(() => { window.__cardObserver.disconnect(); return window.__cardMoves; }), 0, 'A progress update must not detach and reinsert the active card');
+  const readout = page.locator(`#ytdl-notifications [data-id="${jobId}"] .label`);
+  await readout.evaluate(node => { window.__progressLabelTextNode = node.firstChild; });
+  await emit({ percent: 26, speed: 4.2 * 1048576 });
+  assert.equal(await readout.textContent(), '26% · 4.2 МБ/с');
+  assert.equal(await readout.evaluate(node => node.firstChild === window.__progressLabelTextNode), true, 'Changing measurements must update the existing text node');
+  await emit({ speed: 0 });
+  assert.equal(await readout.textContent(), '25% · 0.0 МБ/с', 'An actual zero-speed measurement must remain visible');
+  for (const width of [1280, 360]) {
+    await page.setViewportSize({ width, height: 900 }); await menu.setViewportSize({ width: Math.min(width, 520), height: 900 });
+    await checkSize({ downloaded: 0 }, "Скачано 0,0 МБ из 850,0 МБ");
+    await checkSize({}, "Скачано 123,4 МБ из 850,0 МБ");
+    await checkSize({ track: "audio", downloaded: 12.8 * 1048576, total: 24.4 * 1048576 }, "Скачано 12,8 МБ из 24,4 МБ");
+    await checkSize({ downloaded: 12.8 * 1048576, total: 0 }, "Скачано 12,8 МБ");
+    await checkSize({ downloaded: null, total: null }, "");
+    await checkSize({ stage: "encoding", engine: "nvenc" }, "");
+    assert.equal(await page.locator(`#ytdl-notifications [data-id="${jobId}"] .stage`).textContent(), "Перекодирование · NVIDIA NVENC");
+    await checkSize({ stage: "remuxing", engine: "copy", percent: 35, processedSeconds: 84, durationSeconds: 240, written: 1234.5 * 1048576, speed: "120x", eta: 1 }, "Обработано 1:24 из 4:00 · Записано 1 234,5 МБ", "Обработано 1:24 из 4:00 · Записано 1 234,5 МБ · осталось ≈ 1 с");
+    assert.equal(await page.locator(`#ytdl-notifications [data-id="${jobId}"] .stage`).textContent(), "Подготовка файла · без перекодирования");
+    await checkSize({ stage: "audio", engine: "cpu", percent: 35, processedSeconds: 84, durationSeconds: 240, written: 1234.5 * 1048576, speed: "48x" }, "Обработано 1:24 из 4:00 · Записано 1 234,5 МБ");
+    assert.equal(await page.locator(`#ytdl-notifications [data-id="${jobId}"] .stage`).textContent(), "Обработка аудио · CPU");
+    await checkSize({ stage: "finalizing", engine: "copy", percent: 99, processedSeconds: 240, durationSeconds: 240, written: 1234.5 * 1048576, speed: "", eta: null, message: "Финализация файла" }, "Обработано 4:00 из 4:00 · Записано 1 234,5 МБ");
+    assert.equal(await page.locator(`#ytdl-notifications [data-id="${jobId}"] .stage`).textContent(), "Финализация файла");
+    await checkSize({ stage: "merging", percent: 35, processedSeconds: 84, durationSeconds: 240, written: 1234.5 * 1048576, speed: "38.6x", eta: 4.1 }, "Обработано 1:24 из 4:00 · Записано 1 234,5 МБ", "Обработано 1:24 из 4:00 · Записано 1 234,5 МБ · осталось ≈ 5 с");
+    await page.locator(`#ytdl-notifications [data-id="${jobId}"]`).screenshot({ path: path.join(artifacts, `progress-merging-${width}.png`) });
+    await checkSize({ stage: "saving", copied: 256 * 1048576, total: 1024 * 1048576, percent: 25, speed: null }, "Сохранено 256,0 МБ из 1 024,0 МБ");
+    await emit(); await page.waitForTimeout(400);
+    results.push({ width, state: "25%", toast: await sample(toastFill, false), history: await sample(historyFill, false) });
+    await emit({ percent: 90 }); await page.waitForTimeout(350);
+    // Enter waiting from a wide filled bar to catch an unwanted width transition.
+    await emit({ percent: null, stage: "preparing" });
+    results.push({ width, state: "waiting", toast: await sample(toastFill, true), history: await sample(historyFill, true) });
+    await page.locator(`#ytdl-notifications [data-id="${jobId}"]`).screenshot({ path: path.join(artifacts, `progress-waiting-${width}.png`) });
+    await emit({ percent: 25 }); await page.waitForTimeout(350);
+    results.push({ width, state: "resumed", toast: await sample(toastFill, false), history: await sample(historyFill, false) });
+    await page.locator(`#ytdl-notifications [data-id="${jobId}"]`).screenshot({ path: path.join(artifacts, `progress-downloading-${width}.png`) });
+  }
+  for (const status of ["complete", "error", "cancelled"]) {
+    await checkSize({ status, stage: status, percent: status === "complete" ? 100 : 25, result: status === "complete" ? { filename: "Проверка.mp4", size: 1024.5 * 1048576 } : undefined }, status === "complete" ? "Размер файла: 1 024,5 МБ" : "");
+    await page.waitForTimeout(350);
+    assert.equal(await historyFill.count(), 0, `${status}: terminal jobs move out of settings`);
+    assert.equal(await toastFill.evaluate(node => node.getRootNode().getAnimations().filter(item => item.effect?.target === node && item instanceof CSSAnimation).length), 0, `${status}: moving effects must stop`);
+  }
+  await page.emulateMedia({ reducedMotion: "reduce" }); await menu.emulateMedia({ reducedMotion: "reduce" });
+  for (const percent of [25, null]) {
+    await emit({ percent }); await page.waitForTimeout(30);
+    for (const fill of [toastFill, historyFill]) assert.equal(await fill.evaluate(node => node.getRootNode().getAnimations().filter(item => item.effect?.target === node).length), 0, "Reduced motion must disable moving effects");
+  }
+  assert.deepEqual(errors, []);
+  await fs.writeFile(path.join(artifacts, "progress-motion-result.json"), JSON.stringify({ version: JSON.parse(await fs.readFile(path.join(root, "extension/manifest.json"))).version, actualYouTubeToast: true, stages: results, terminalEffectsStopped: true, reducedMotion: true }, null, 2));
+  console.log("Progress motion passed: actual Edge/YouTube toast, stable readouts and history cards, zero-speed display, highlight clipping, bounded waiting motion, resume, narrow layout, terminal states and reduced motion.");
+} finally {
+  await context.close();
+  if (path.dirname(path.resolve(profile)) === path.resolve(os.tmpdir()) && path.basename(profile).startsWith("ytdl-motion-test-")) await fs.rm(profile, { recursive: true, force: true });
+}

tests/session.test.mjs

@@ -0,0 +1,93 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readSession, SESSION_PERMISSION } from "../extension/session.js";
+
+const sampleCookie = value => ({ name: "SAPISID", value, domain: ".youtube.com", path: "/", secure: true, httpOnly: true, hostOnly: false });
+
+test("session access needs both opt-in and permission and does not return secrets to the UI", async () => {
+  let enabled = false, permission = false, reads = 0;
+  globalThis.chrome = {
+    storage: { local: { get: async () => ({ youtubeSession: enabled }) } },
+    permissions: { contains: async () => permission },
+    cookies: {
+      getAllCookieStores: async () => [{ id: "current-profile", tabIds: [42] }],
+      getAll: async options => {
+        reads++; assert.equal(options.domain, "youtube.com"); assert.equal(options.storeId, "current-profile");
+        return [sampleCookie("synthetic-session"), { ...sampleCookie("other"), domain: ".google.com" },
+          { ...sampleCookie("evil"), domain: "youtube.com.evil.test" }, { ...sampleCookie("expired"), expirationDate: 1 },
+          { ...sampleCookie("partitioned"), partitionKey: { topLevelSite: "https://another.test" } }];
+      },
+    },
+  };
+  assert.equal((await readSession(42)).status, "disabled"); assert.equal(reads, 0);
+  enabled = true;
+  assert.equal((await readSession(42)).status, "permission_required"); assert.equal(reads, 0);
+  permission = true;
+  const status = await readSession(42);
+  assert.equal(status.status, "connected"); assert.ok(!JSON.stringify(status).includes("synthetic-session"));
+  const authenticated = await readSession(42, true);
+  assert.equal(authenticated.cookies.length, 1); assert.equal(authenticated.cookies[0].value, "synthetic-session");
+  await assert.rejects(readSession(999, true), /профиль вкладки/);
+});
+
+test("background passes fresh YouTube cookies to both worker actions and never persists them", async () => {
+  const storage = {}, requests = [], listeners = {}, pendingUi = new Map();
+  let permission = false, cookieValue = "synthetic-original", cookieReads = 0, nativeListener;
+  const noEvent = { addListener() {} };
+  const native = {
+    onMessage: { addListener(listener) { nativeListener = listener; } }, onDisconnect: noEvent, disconnect() {},
+    postMessage(message) {
+      requests.push(message);
+      const result = message.action === "hello" ? { version: "1.3.2", ready: true, supportsBrowserCookies: true } : message.action === "ping" ? { alive: true }
+        : message.action === "download" ? { jobId: "auth-test-job" } : { title: "Synthetic video", videos: [], audios: [] };
+      queueMicrotask(() => nativeListener({ id: message.id, ok: true, result }));
+    },
+  };
+  globalThis.chrome = {
+    runtime: { id: "test-id", getManifest: () => ({ version: "1.4.5" }), getURL: name => `chrome-extension://test-id/${name}`, connectNative: () => native,
+      onConnect: { addListener(listener) { listeners.connect = listener; } }, onMessage: noEvent },
+    permissions: { contains: async () => permission, remove: async input => { assert.deepEqual(input, SESSION_PERMISSION); permission = false; return true; } },
+    cookies: { getAllCookieStores: async () => [{ id: "0", tabIds: [42] }], getAll: async () => { cookieReads++; return [sampleCookie(cookieValue)]; } },
+    storage: { local: { get: async key => Object.fromEntries((Array.isArray(key) ? key : [key]).map(name => [name, storage[name]])),
+      set: async values => Object.assign(storage, structuredClone(values)) } },
+    notifications: { clear: async () => {}, create: async () => {}, onButtonClicked: noEvent },
+    tabs: { sendMessage: async () => {} }, action: { onClicked: noEvent, setBadgeText() {}, setBadgeBackgroundColor() {} },
+  };
+  await import("../extension/background.js?session-test");
+  let uiListener;
+  listeners.connect({ name: "ytdl-ui", sender: { id: "test-id", url: "chrome-extension://test-id/downloader.html" },
+    onDisconnect: noEvent, onMessage: { addListener(listener) { uiListener = listener; } },
+    postMessage(message) { if (message.id) { const done = pendingUi.get(message.id); pendingUi.delete(message.id); done(message); } } });
+  const call = (action, payload = {}) => new Promise(resolve => {
+    const id = crypto.randomUUID(); pendingUi.set(id, resolve); uiListener({ id, action, payload });
+  });
+  assert.equal((await call("hello")).ok, true);
+  assert.equal((await call("session_enable", { enabled: true, tabId: 42 })).ok, false);
+  const url = "https://www.youtube.com/watch?v=jNQXAC9IVRw";
+  await call("inspect", { url, tabId: 42, browserCookies: [sampleCookie("caller-injected")] });
+  assert.equal(cookieReads, 0); assert.ok(!requests.at(-1).payload.browserCookies);
+  permission = true;
+  const enabled = await call("session_enable", { enabled: true, tabId: 42 });
+  assert.equal(enabled.result.status, "connected"); assert.ok(!JSON.stringify(enabled).includes(cookieValue));
+  await call("inspect", { url, tabId: 42 });
+  assert.equal(requests.at(-1).payload.browserCookies[0].value, cookieValue);
+  const inspectionRequests = requests.filter(request => request.action === "inspect").length;
+  await call("inspect", { url, tabId: 42 });
+  assert.equal(requests.filter(request => request.action === "inspect").length, inspectionRequests, "Reuse a recently inspected video's quality without another YouTube request");
+  await call("inspect", { url, tabId: 42, refresh: true });
+  assert.equal(requests.filter(request => request.action === "inspect").length, inspectionRequests + 1, "Explicit refresh bypasses the summary cache");
+  cookieValue = "synthetic-rotated";
+  await call("download", { url, tabId: 42, title: "Test", folder: "D:/Videos" });
+  assert.equal(requests.at(-1).payload.browserCookies[0].value, cookieValue);
+  nativeListener({ event: "job", job: { id: "auth-test-job", status: "complete", stage: "complete", result: { title: "Test", filename: "test.mp4", path: "D:/Videos/test.mp4" } } });
+  await new Promise(resolve => setTimeout(resolve, 20));
+  assert.ok(!JSON.stringify(storage).includes("synthetic-")); assert.ok(!JSON.stringify(storage).includes("browserCookies"));
+  await call("session_enable", { enabled: false, tabId: 42 });
+  const readsBefore = cookieReads;
+  await call("inspect", { url, tabId: 42 });
+  assert.equal(cookieReads, readsBefore); assert.ok(!requests.at(-1).payload.browserCookies);
+  // An expired/removed permission must still allow ordinary public downloads.
+  storage.youtubeSession = true;
+  assert.equal((await call("inspect", { url, tabId: 42, refresh: true })).ok, true);
+  assert.ok(!requests.at(-1).payload.browserCookies);
+});

tests/site.test.mjs

@@ -0,0 +1,73 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { createServer } from "node:http";
+import { chromium } from "playwright";
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const version = JSON.parse(await fs.readFile(path.join(root,"extension/manifest.json"),"utf8")).version;
+const artifacts = path.join(root, "test-artifacts");
+await fs.mkdir(artifacts, { recursive: true });
+const server = createServer(async (request, response) => {
+  try {
+    const url = new URL(request.url, "http://localhost");
+    if (!url.pathname.startsWith("/YouTubeDL/")) { response.writeHead(404).end(); return; }
+    const relative = decodeURIComponent(url.pathname.slice("/YouTubeDL/".length)) || "index.html";
+    const file = path.resolve(root,"site",relative);
+    if (!file.startsWith(path.resolve(root,"site") + path.sep)) { response.writeHead(400).end(); return; }
+    const type = {".html":"text/html; charset=utf-8",".js":"text/javascript",".css":"text/css",".png":"image/png",".svg":"image/svg+xml"}[path.extname(file)] || "application/octet-stream";
+    response.writeHead(200,{"Content-Type":type});response.end(await fs.readFile(file));
+  } catch { response.writeHead(404).end(); }
+});
+await new Promise(resolve => server.listen(0,"127.0.0.1",resolve));
+const local = `http://127.0.0.1:${server.address().port}/YouTubeDL/`;
+const target = process.env.YTDL_SITE_URL || local;
+let browser;
+try {
+  browser = await chromium.launch({ headless:true, executablePath:process.env.YTDL_TEST_BROWSER || "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe" });
+  const context = await browser.newContext({ viewport:{width:1440,height:1050}, reducedMotion:"reduce", colorScheme:"light" });
+  const page = await context.newPage(), failures=[];
+  page.on("pageerror",error => failures.push(error.message));
+  page.on("response",response => { if (response.url().startsWith(target) && response.status() >= 400) failures.push(`${response.status()} ${response.url()}`); });
+  await page.goto(target,{waitUntil:"networkidle"});
+  assert.equal(await page.locator("h1").count(),1);
+  await page.locator(".hero .primary").click();
+  assert.equal(new URL(page.url()).hash,"#install");
+  assert.ok(await page.locator(".download-grid").isVisible());
+  assert.equal(await page.locator('[data-download="extension"]').getAttribute("href"),`https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/download/v${version}/YouTubeDL-${version}.zip`);
+  assert.equal(await page.locator('[data-download="helper"]').getAttribute("href"),"https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/download/v1.4.5/YouTubeDL-Helper-Setup.exe");
+  await page.locator('[data-screenshot="light"]').click();
+  await page.locator("#menu-screenshot").evaluate(image => image.decode());
+  assert.match(await page.locator("#menu-screenshot").getAttribute("src"), /menu-light\.png$/);
+  await page.locator('[data-screenshot="dark"]').click();
+  await page.locator("#menu-screenshot").evaluate(image => image.decode());
+  await page.locator("#theme-toggle").click();
+  assert.equal(await page.locator("html").getAttribute("data-theme"),"dark");
+  await page.reload({waitUntil:"networkidle"});
+  assert.equal(await page.locator("html").getAttribute("data-theme"),"dark");
+  await page.locator("#theme-toggle").click();
+  await page.evaluate(() => scrollTo(0,0));
+  await page.locator(".hero").screenshot({path:path.join(artifacts,"site-hero.png")});
+  await page.locator(".download-grid").screenshot({path:path.join(artifacts,"site-downloads.png")});
+  await page.screenshot({path:path.join(artifacts,"site-desktop.png"),fullPage:true});
+  for (const width of [320,390,768]) {
+    await page.setViewportSize({width,height:844});
+    await page.evaluate(() => scrollTo(0,0));
+    const overflow = await page.evaluate(() => [...document.querySelectorAll("body *")].filter(node => node.getBoundingClientRect().right > innerWidth + 1 && getComputedStyle(node).position !== "absolute").map(node => ({tag:node.tagName,class:node.className,right:Math.round(node.getBoundingClientRect().right)})));
+    if (await page.evaluate(() => document.documentElement.scrollWidth > innerWidth)) await page.screenshot({path:path.join(artifacts,`site-overflow-${width}.png`),fullPage:true});
+    assert.ok(await page.evaluate(() => document.documentElement.scrollWidth <= innerWidth),`No horizontal overflow at ${width}px: ${JSON.stringify(overflow)}`);
+    assert.ok(await page.locator("h1").isVisible());
+    await page.locator('nav a[href="#install"]').click();
+    assert.equal(new URL(page.url()).hash,"#install");
+    const summary = page.locator(".faqs summary").first();await summary.click();
+    assert.equal(await page.locator(".faqs details").first().getAttribute("open"),"");
+    await summary.click();
+    await page.evaluate(() => scrollTo(0,0));
+    if(width===390) await page.screenshot({path:path.join(artifacts,"site-mobile.png"),fullPage:true});
+  }
+  const images=await page.locator("img").evaluateAll(nodes => nodes.map(image=>({src:image.getAttribute("src"),okay:image.complete&&image.naturalWidth>0})));
+  assert.ok(images.every(image=>image.okay),JSON.stringify(images));
+  assert.deepEqual(failures,[]);
+  await fs.writeFile(path.join(artifacts,"site-check.json"),JSON.stringify({url:target,desktop:"passed",widths:[320,390,768],themes:"passed",screenshots:"passed",downloadLinks:"passed",faq:"passed",errors:failures},null,2));
+  console.log(`Site passed at ${target}: desktop/mobile, Pages subpath, download links, theme persistence, screenshots, FAQ and no console/HTTP errors.`);
+} finally { if(browser)await browser.close();await new Promise(resolve=>server.close(resolve)); }

tests/test-native-registration.ps1

@@ -0,0 +1,22 @@
+param(
+    [Parameter(Mandatory=$true)][string]$Name,
+    [Parameter(Mandatory=$true)][string]$ManifestPath,
+    [switch]$Remove
+)
+$ErrorActionPreference = 'Stop'
+if ($Name -notmatch '^com\.youtubedl\.test_[a-f0-9]{16}$') { throw 'Only isolated test hosts are allowed.' }
+$taskManifest = [IO.Path]::GetFullPath($ManifestPath)
+$taskKey = "Registry::HKEY_CURRENT_USER\Software\Microsoft\Edge\NativeMessagingHosts\$Name"
+if (Test-Path -LiteralPath $taskKey) {
+    $taskRegistered = (Get-Item -LiteralPath $taskKey).GetValue('')
+    if ($taskRegistered -and $taskRegistered -ne $taskManifest) { throw 'Test registration belongs to another path.' }
+}
+if ($Remove) {
+    if (Test-Path -LiteralPath $taskKey) { Remove-Item -LiteralPath $taskKey }
+} else {
+    $taskData = Get-Content -LiteralPath $taskManifest -Raw | ConvertFrom-Json
+    if ($taskData.name -ne $Name) { throw 'Wrong test host manifest.' }
+    New-Item -Path $taskKey -Force | Out-Null
+    Set-Item -LiteralPath $taskKey -Value $taskManifest
+    if ((Get-Item -LiteralPath $taskKey).GetValue('') -ne $taskManifest) { throw 'Test registration was not written.' }
+}

tests/test_host.py

@@ -0,0 +1,228 @@
+import io
+import json
+import os
+import struct
+import tempfile
+import unittest
+from pathlib import Path
+from unittest.mock import patch
+
+from host.common import safe_filename, select_streams, validate_download, youtube_url
+from host.media import encoding_plan, ffmpeg_command
+from host.protocol import MAX_MESSAGE, read_message, write_message
+from host.worker import publish_file
+from host.main import NativeHost
+from host.session import apply_cookies, validate_cookies, public_error
+
+
+class HostTests(unittest.TestCase):
+    def test_fragment_access_failure_retries_and_preserves_the_original_error(self):
+        from unittest.mock import MagicMock
+        from yt_dlp.utils import DownloadError
+        from host.worker import download
+        first, second = MagicMock(), MagicMock()
+        first.__enter__.return_value = first; second.__enter__.return_value = second
+        handles = []
+        def fail(ydl):
+            # Reproduce a downloader retaining its .part handle during failure.
+            part = Path(ydl.params["outtmpl"].replace("%(ext)s", "mp4") + ".part")
+            handles.append(part.open("wb"))
+            raise DownloadError("HTTP Error 403: Forbidden")
+        def create_ydl(params):
+            current = first if not handles else second
+            current.params = params
+            current.extract_info.side_effect = lambda *args, **kwargs: fail(current)
+            return current
+        with tempfile.TemporaryDirectory() as folder:
+            try:
+                with patch("yt_dlp.YoutubeDL", side_effect=create_ydl), patch("host.worker.ydl_options", return_value={}), \
+                     patch("host.worker.time.sleep"), patch("host.worker.emit") as emit:
+                    with self.assertRaisesRegex(DownloadError, "HTTP Error 403"):
+                        download({"url": "https://youtu.be/jNQXAC9IVRw", "folder": folder}, [])
+                    self.assertEqual(len(handles), 2)
+                    self.assertTrue(any("повторяю загрузку" in str(call) for call in emit.call_args_list))
+            finally:
+                for handle in handles: handle.close()
+
+    def test_transient_youtube_challenge_is_retried_once_without_browser_cookies(self):
+        from unittest.mock import MagicMock
+        from yt_dlp.utils import DownloadError
+        first, second = MagicMock(), MagicMock()
+        first.__enter__.return_value = first; second.__enter__.return_value = second
+        first.extract_info.side_effect = DownloadError("Sign in to confirm you’re not a bot")
+        second.extract_info.return_value = {"id": "jNQXAC9IVRw"}
+        with patch("yt_dlp.YoutubeDL", side_effect=[first, second]), patch("host.worker.ydl_options", return_value={}), \
+             patch("host.worker.summarize", side_effect=lambda info: info), patch("host.worker.time.sleep"):
+            from host.worker import inspect
+            self.assertEqual(inspect("https://youtu.be/jNQXAC9IVRw")["id"], "jNQXAC9IVRw")
+        first.cookiejar.set_cookie.assert_not_called(); second.cookiejar.set_cookie.assert_not_called()
+
+    def test_browser_session_is_youtube_only_and_never_saved_to_a_cookie_file(self):
+        from urllib.request import Request
+        from yt_dlp import YoutubeDL
+        from yt_dlp.cookies import YoutubeDLCookieJar
+        cookie = {"name": "SAPISID", "value": "synthetic-cookie", "domain": ".youtube.com", "path": "/", "secure": True, "httpOnly": True}
+        with patch.object(YoutubeDLCookieJar, "save", side_effect=AssertionError("Cookies must stay in memory")):
+            with YoutubeDL({"quiet": True}) as ydl:
+                apply_cookies(ydl, [cookie])
+                self.assertIsNone(ydl.cookiejar.filename)
+                request = Request("https://www.youtube.com/watch?v=jNQXAC9IVRw")
+                ydl.cookiejar.add_cookie_header(request)
+                self.assertIn("SAPISID=synthetic-cookie", request.get_header("Cookie"))
+                unrelated = Request("https://www.google.com/")
+                ydl.cookiejar.add_cookie_header(unrelated)
+                self.assertIsNone(unrelated.get_header("Cookie"))
+        for invalid in [{**cookie, "domain": ".google.com"}, {**cookie, "domain": "youtube.com.evil.test"},
+                        {**cookie, "value": "secret\r\nInjected: header"}, {**cookie, "expirationDate": float("nan")}, {**cookie, "name": "bad=name"}]:
+            with self.assertRaises(ValueError): validate_cookies([invalid])
+
+    def test_native_inspection_passes_cookies_only_to_worker_and_not_to_reply(self):
+        with tempfile.TemporaryDirectory() as folder, patch("host.main.ROOT", Path(folder)):
+            output = io.BytesIO(); host = NativeHost(output)
+            cookie = {"name": "SID", "value": "synthetic-session", "domain": ".youtube.com", "path": "/"}
+            try:
+                with patch.object(host, "worker", return_value={"title": "Test"}) as worker:
+                    host.handle({"id": "inspect-auth", "action": "inspect", "payload": {"url": "https://youtu.be/jNQXAC9IVRw", "browserCookies": [cookie]}})
+                    self.assertEqual(worker.call_args.args[1]["browserCookies"][0]["value"], cookie["value"])
+                self.assertNotIn(b"synthetic-session", output.getvalue())
+                self.assertNotIn("browserCookies", json.dumps(host.jobs))
+            finally: host.close()
+
+    def test_youtube_login_error_is_distinct_from_helper_connection_failure(self):
+        message = public_error(ValueError("ERROR: Sign in to confirm you’re not a bot"))
+        self.assertIn("Использовать вход в YouTube", message)
+        self.assertIn("Помощник работает", message)
+        self.assertNotIn("cookies-from-browser", message)
+        self.assertIn("отклонил вход", public_error(ValueError("Sign in to confirm"), True))
+
+    def test_youtube_urls_are_canonical_and_do_not_allow_arbitrary_hosts(self):
+        expected = "https://www.youtube.com/watch?v=jNQXAC9IVRw"
+        for value in [expected + "&list=other", "https://youtu.be/jNQXAC9IVRw?t=2", "https://www.youtube.com/shorts/jNQXAC9IVRw"]:
+            self.assertEqual(youtube_url(value), expected)
+        for value in ["https://youtube.com.evil.test/watch?v=jNQXAC9IVRw", "https://127.0.0.1/watch?v=jNQXAC9IVRw", "https://youtube.com@evil.test/watch?v=jNQXAC9IVRw", "file:///test", "https://www.youtube.com:444/watch?v=jNQXAC9IVRw", "https://www.youtube.com/@channel"]:
+            with self.assertRaises(ValueError): youtube_url(value)
+
+    def test_separate_audio_is_added_and_video_only_stays_single(self):
+        info = {"formats": [{"format_id": "18", "vcodec": "h264", "acodec": "aac", "height": 360},
+                            {"format_id": "137", "vcodec": "h264", "acodec": "none", "height": 1080},
+                            {"format_id": "140", "vcodec": "none", "acodec": "aac"}]}
+        base = {"mode": "video", "videoId": "137", "audioId": "best"}
+        self.assertEqual(select_streams(info, base), "137+140")
+        self.assertEqual(select_streams(info, {**base, "mode": "video_only"}), "137")
+        self.assertEqual(select_streams(info, {**base, "videoId": "18"}), "18")
+        self.assertEqual(select_streams(info, {**base, "mode": "audio"}), "140")
+
+    def test_download_does_not_accept_format_selector_injection(self):
+        with tempfile.TemporaryDirectory() as folder:
+            base = {"url": "https://youtu.be/jNQXAC9IVRw", "folder": folder, "videoId": "137+bestaudio"}
+            with self.assertRaises(ValueError): validate_download(base)
+            self.assertEqual(validate_download({**base, "videoId": "137"})["container"], "mp4")
+            with self.assertRaises(ValueError): validate_download({**base, "videoId": "137", "container": "exe"})
+
+    def test_gpu_is_used_only_when_video_needs_transcoding(self):
+        media = {"streams": [{"codec_type": "video", "codec_name": "vp9", "pix_fmt": "yuv420p"}, {"codec_type": "audio", "codec_name": "opus"}]}
+        options = {"mode": "video", "container": "mp4", "codec": "auto", "engine": "auto"}
+        plan = encoding_plan(options, media, ["h264", "hevc", "av1"])
+        self.assertEqual((plan["video"], plan["audio"], plan["engine"]), ("h264", "aac", "nvenc"))
+        copied = encoding_plan({**options, "container": "mkv"}, media, ["h264"])
+        self.assertEqual((copied["video"], copied["audio"], copied["engine"]), ("copy", "copy", "copy"))
+        cpu = encoding_plan(options, media, [])
+        self.assertEqual(cpu["engine"], "cpu")
+        with self.assertRaises(ValueError): encoding_plan({**options, "engine": "nvenc"}, media, [])
+        with self.assertRaises(ValueError): encoding_plan({**options, "codec": "copy"}, media, [])
+
+    def test_hdr_is_not_silently_converted_to_h264(self):
+        media = {"streams": [{"codec_type": "video", "codec_name": "vp9", "pix_fmt": "yuv420p10le", "color_transfer": "smpte2084"}, {"codec_type": "audio", "codec_name": "opus"}]}
+        options = {"mode": "video", "container": "mp4", "codec": "auto", "engine": "auto"}
+        self.assertEqual(encoding_plan(options, media, ["hevc"])["video"], "hevc")
+        with self.assertRaises(ValueError): encoding_plan({**options, "codec": "h264"}, media, ["h264"])
+
+    def test_amf_requires_measured_codec_and_10bit_support(self):
+        media = {"streams": [{"codec_type": "video", "codec_name": "vp9", "pix_fmt": "yuv420p"}, {"codec_type": "audio", "codec_name": "opus"}]}
+        options = {"mode": "video", "container": "mp4", "codec": "hevc", "engine": "auto", "preset": "balanced", "bitrate": 256}
+        self.assertEqual(encoding_plan(options, media, {"amf": ["hevc"]})["engine"], "amf")
+        self.assertEqual(encoding_plan(options, media, {"nvenc": ["hevc"], "amf": ["hevc"]})["engine"], "nvenc")
+        with self.assertRaisesRegex(ValueError, "AMD AMF"):
+            encoding_plan({**options, "engine": "amf"}, media, {})
+        media["streams"][0].update(pix_fmt="yuv420p10le", color_transfer="smpte2084")
+        self.assertEqual(encoding_plan(options, media, {"amf": ["hevc"]})["engine"], "cpu")
+        plan = encoding_plan({**options, "engine": "amf"}, media, {"amf": ["hevc"], "amf10bit": ["hevc"]})
+        self.assertTrue(plan["tenBit"])
+        with patch("host.media.tool", return_value="ffmpeg"):
+            command = ffmpeg_command("source.mkv", "out.mp4", options, plan)
+        self.assertIn("hevc_amf", command); self.assertIn("p010le", command); self.assertIn("main10", command)
+        self.assertIn("d3d11va", command); self.assertNotIn("cuda", command)
+
+    def test_audio_and_video_only_output_maps(self):
+        source = {"streams": [{"codec_type": "video", "codec_name": "h264"}, {"codec_type": "audio", "codec_name": "aac"}]}
+        options = {"mode": "video_only", "container": "mp4", "codec": "auto", "engine": "auto", "preset": "balanced", "bitrate": 256}
+        with patch("host.media.tool", return_value="ffmpeg"):
+            command = ffmpeg_command("source.mkv", "out.mp4", options, encoding_plan(options, source, []))
+        self.assertIn("-an", command)
+        self.assertNotIn("0:a:0", command)
+        audio = encoding_plan({**options, "mode": "audio", "container": "mp3"}, source, [])
+        self.assertEqual((audio["video"], audio["audio"], audio["engine"]), (None, "libmp3lame", "cpu"))
+
+    def test_protocol_uses_utf8_byte_lengths_and_handles_partial_reads(self):
+        message = {"text": "Русский путь 🎬"}
+        stream = io.BytesIO()
+        write_message(stream, message)
+        self.assertEqual(struct.unpack("<I", stream.getvalue()[:4])[0], len(stream.getvalue()) - 4)
+        class Partial(io.BytesIO):
+            def read(self, count=-1): return super().read(min(count, 2))
+        self.assertEqual(read_message(Partial(stream.getvalue())), message)
+        self.assertIsNone(read_message(io.BytesIO()))
+        with self.assertRaises(ValueError): read_message(io.BytesIO(struct.pack("<I", MAX_MESSAGE + 1)))
+        with self.assertRaises(EOFError): read_message(io.BytesIO(struct.pack("<I", 5) + b"{}"))
+
+    def test_filename_is_safe_and_existing_files_are_never_overwritten(self):
+        self.assertEqual(safe_filename("../CON:bad/name", "video"), "_CON_bad_name")
+        self.assertEqual(safe_filename("CON", "video"), "_CON")
+        with tempfile.TemporaryDirectory() as folder:
+            root = Path(folder); original = root / "video.mp4"; original.write_bytes(b"original")
+            source = root / "temp.mp4"; source.write_bytes(b"new")
+            saved = publish_file(source, root, "video", "mp4")
+            self.assertEqual(saved.name, "video (1).mp4")
+            self.assertEqual(original.read_bytes(), b"original")
+            self.assertEqual(saved.read_bytes(), b"new")
+
+    def test_dependency_install_refreshes_capabilities_before_reporting_completion(self):
+        with tempfile.TemporaryDirectory() as folder, patch("host.main.ROOT", Path(folder)):
+            host = NativeHost(io.BytesIO())
+            host._capabilities = {"ready": False}
+            host.jobs["install"] = {"id": "install", "status": "running", "kind": "dependency"}
+            try:
+                with patch.object(host, "worker", return_value={"title": "Node.js"}), patch.object(host, "event") as event:
+                    event.side_effect = lambda *args, **kwargs: self.assertIsNone(host._capabilities)
+                    host.run_job("install", {"dependency": "node"}, "dependency_install")
+                    self.assertEqual(event.call_args.kwargs["status"], "complete")
+                with patch.object(host, "worker", side_effect=ValueError("install failed")), patch.object(host, "event") as event:
+                    host._capabilities = {"ready": False}
+                    event.side_effect = lambda *args, **kwargs: self.assertIsNone(host._capabilities)
+                    host.run_job("install", {"dependency": "node"}, "dependency_install")
+                    self.assertEqual(event.call_args.kwargs["status"], "error")
+            finally:
+                host.close()
+
+    def test_completed_file_can_be_revealed_after_native_host_restart(self):
+        with tempfile.TemporaryDirectory() as folder, patch("host.main.ROOT", Path(folder)):
+            saved = Path(folder) / "finished.mp4"
+            saved.write_bytes(b"media")
+            first = NativeHost(io.BytesIO())
+            first.jobs["completed"] = {"id": "completed", "status": "running", "createdAt": 1}
+            first.event("completed", status="complete", result={"path": str(saved)})
+            first.close()
+            output = io.BytesIO()
+            restarted = NativeHost(output)
+            try:
+                with patch("host.main.subprocess.Popen") as launch:
+                    restarted.handle({"id": "reveal", "action": "reveal", "payload": {"jobId": "completed"}})
+                output.seek(0)
+                self.assertTrue(read_message(output)["ok"])
+                if os.name == "nt":
+                    self.assertEqual(launch.call_args.args[0][-1], str(saved))
+            finally:
+                restarted.close()
+
+
+if __name__ == "__main__": unittest.main()

tests/test_processing.py

@@ -0,0 +1,205 @@
+import functools
+import io
+import json
+import os
+import subprocess
+import sys
+import tempfile
+import threading
+import time
+import unittest
+from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
+from pathlib import Path
+from unittest.mock import patch
+
+from host.common import validate_download
+from host.main import NativeHost
+from host.media import NO_WINDOW, ROOT, probe, tool
+from host.processes import ProcessTree
+from host.worker import convert, download
+
+
+class ProcessingTests(unittest.TestCase):
+    def test_audio_conversion_and_video_conversion_report_the_actual_engine(self):
+        runtime = ROOT / ".runtime"
+        runtime.mkdir(exist_ok=True)
+        with tempfile.TemporaryDirectory(prefix="processing-stages-", dir=runtime) as directory:
+            source = Path(directory) / "source.mkv"
+            subprocess.run([tool("ffmpeg"), "-nostdin", "-v", "error", "-y", "-f", "lavfi", "-i", "testsrc2=size=160x90:rate=24",
+                            "-f", "lavfi", "-i", "sine=frequency=440:sample_rate=48000", "-t", "3", "-c:v", "libx264", "-preset", "ultrafast", "-c:a", "libopus", str(source)],
+                           creationflags=NO_WINDOW, stdin=subprocess.DEVNULL, check=True, timeout=30)
+            media = probe(source)
+            for codec, stage in [("auto", "audio"), ("h264", "encoding")]:
+                target = Path(directory) / f"{codec}.mp4"
+                events = []
+                options = {"mode": "video", "container": "mp4", "codec": codec, "engine": "auto" if codec == "auto" else "cpu", "preset": "fast", "bitrate": 192}
+                with patch("host.worker.emit", side_effect=lambda kind, **data: events.append({"type": kind, **data})):
+                    plan = convert(source, target, options, media, {"nvenc": ["h264"]})
+                self.assertEqual(plan["engine"], "cpu")
+                self.assertEqual(plan["video"], "copy" if codec == "auto" else "h264")
+                self.assertTrue(any(event.get("stage") == stage and event.get("engine") == "cpu" for event in events), events)
+                self.assertFalse(any(event.get("stage") == "merging" for event in events), events)
+                self.assertTrue(any(event.get("stage") == "finalizing" and event.get("percent") == 99 and not event.get("speed") for event in events), events)
+                finalizing = next(index for index, event in enumerate(events) if event.get("stage") == "finalizing")
+                self.assertTrue(all(event.get("stage") == "finalizing" for event in events[finalizing:]), events)
+                self.assertEqual({s.get("codec_name") for s in probe(target)["streams"]}, {"h264", "aac"})
+
+    def test_late_completion_cannot_replace_cancellation(self):
+        host = NativeHost(io.BytesIO())
+        try:
+            host.jobs["late"] = {"id": "late", "status": "running", "stage": "cancelling", "cancelling": True}
+            host.event("late", status="complete", stage="complete")
+            self.assertEqual(host.jobs["late"]["status"], "running")
+            host.event("late", status="cancelled", stage="cancelled", cancelling=False)
+            host.event("late", status="complete", stage="complete")
+            self.assertEqual(host.jobs["late"]["status"], "cancelled")
+        finally: host.close()
+
+    def test_work_folder_validation_and_default(self):
+        with tempfile.TemporaryDirectory() as folder:
+            payload = {"url": "https://youtu.be/jNQXAC9IVRw", "folder": folder}
+            self.assertEqual(validate_download(payload)["workFolder"], str(Path(folder).resolve()))
+            with self.assertRaisesRegex(ValueError, "Рабочая папка"):
+                validate_download({**payload, "workFolder": str(Path(folder) / "missing")})
+
+    @unittest.skipUnless(os.name == "nt", "Native worker process and disk cleanup")
+    def test_native_worker_cancel_removes_both_workspaces_and_stops_ffmpeg(self):
+        runtime = ROOT / ".runtime"
+        runtime.mkdir(exist_ok=True)
+        with tempfile.TemporaryDirectory(dir=runtime) as work, tempfile.TemporaryDirectory() as target:
+            fixture = Path(work) / "host"
+            fixture.mkdir()
+            (fixture / "worker.py").write_text('''import json,subprocess,sys,tempfile,time
+from pathlib import Path
+task=json.loads(sys.stdin.readline())['payload']
+for folder in [task['workFolder'],task['folder']]:
+    scratch=Path(tempfile.mkdtemp(prefix='.ytdl-',dir=folder))
+    (scratch/'partial.mp4').write_bytes(b'partial')
+    print(json.dumps({'type':'workspace','path':str(scratch)}),flush=True)
+child=subprocess.Popen([task['ffmpeg'],'-nostdin','-v','error','-re','-f','lavfi','-i','testsrc2=size=64x64:rate=10','-f','null','-'],stdin=subprocess.DEVNULL,stdout=subprocess.DEVNULL,stderr=subprocess.DEVNULL)
+print(json.dumps({'type':'progress','stage':'merging','percent':25,'testPid':child.pid}),flush=True)
+time.sleep(60)
+''', encoding="utf-8")
+            for folder in [work, target]: (Path(folder) / "keep.txt").write_text("user file")
+            with patch("host.main.ROOT", Path(work)):
+                host = NativeHost(io.BytesIO())
+                host._capabilities = {}
+                host.jobs["native"] = {"id": "native", "status": "running", "stage": "preparing"}
+                thread = threading.Thread(target=host.run_job, args=("native", {"folder": target, "workFolder": work, "ffmpeg": tool("ffmpeg")}))
+                thread.start()
+                try:
+                    deadline = time.monotonic() + 10
+                    while "testPid" not in host.jobs["native"] and time.monotonic() < deadline: time.sleep(0.025)
+                    pid = host.jobs["native"]["testPid"]
+                    host.handle({"id": "stop", "action": "cancel", "payload": {"jobId": "native"}})
+                    thread.join(timeout=10)
+                    self.assertFalse(thread.is_alive())
+                    self.assertFalse(self.running(pid))
+                    self.assertFalse(host.processes)
+                    for folder in [work, target]:
+                        self.assertFalse(list(Path(folder).glob(".ytdl-*")))
+                        self.assertEqual((Path(folder) / "keep.txt").read_text(), "user file")
+                finally:
+                    host.close()
+                    thread.join(timeout=10)
+
+    @unittest.skipUnless(os.name == "nt", "Actual Windows process-tree regression")
+    def test_cancel_kills_ffmpeg_after_parent_exit_and_keeps_other_job(self):
+        launcher = """import json,subprocess,sys,time
+task=json.loads(sys.stdin.readline())
+child=subprocess.Popen([task['ffmpeg'],'-hide_banner','-loglevel','error','-nostdin','-re','-f','lavfi','-i','testsrc2=size=64x64:rate=10','-f','null','-'],stdin=subprocess.DEVNULL,stdout=subprocess.DEVNULL,stderr=subprocess.DEVNULL)
+print(child.pid,flush=True)
+if not task['exit']:time.sleep(60)
+"""
+        processes = []
+        host = NativeHost(io.BytesIO())
+        try:
+            children = []
+            for exits in (True, False):
+                p = ProcessTree.launch([sys.executable, "-c", launcher], stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                                     stderr=subprocess.DEVNULL, text=True, creationflags=NO_WINDOW)
+                processes.append(p)
+                p.stdin.write(json.dumps({"ffmpeg": tool("ffmpeg"), "exit": exits}) + "\n")
+                p.stdin.close()
+                children.append(int(p.stdout.readline()))
+                if exits: p.wait(timeout=10)
+            host.jobs["cancel"] = {"id": "cancel", "status": "running", "stage": "merging"}
+            host.processes["cancel"] = processes[0]
+            self.assertTrue(self.running(children[0]))
+            self.assertTrue(self.running(children[1]))
+            host.handle({"id": "request", "action": "cancel", "payload": {"jobId": "cancel"}})
+            self.assertEqual(host.jobs["cancel"]["status"], "cancelled")
+            self.assertFalse(self.running(children[0]), "Cancelled FFmpeg must actually exit")
+            self.assertTrue(self.running(children[1]), "A different job's FFmpeg must survive")
+        finally:
+            host.close()
+            for p in processes:
+                tree = getattr(p, "ytdl_process_tree", None)
+                if tree:
+                    tree.terminate(); tree.close()
+                elif p.poll() is None:
+                    p.kill(); p.wait()
+                p.stdout.close()
+            for pid in locals().get("children", []):
+                if self.running(pid):
+                    subprocess.run(["taskkill", "/PID", str(pid), "/T", "/F"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, creationflags=NO_WINDOW, timeout=10)
+
+    @staticmethod
+    def running(pid):
+        import ctypes
+        from ctypes import wintypes
+        api = ctypes.WinDLL("kernel32", use_last_error=True)
+        api.OpenProcess.argtypes = [wintypes.DWORD, wintypes.BOOL, wintypes.DWORD]
+        api.OpenProcess.restype = wintypes.HANDLE
+        api.WaitForSingleObject.argtypes = [wintypes.HANDLE, wintypes.DWORD]
+        api.WaitForSingleObject.restype = wintypes.DWORD
+        api.CloseHandle.argtypes = [wintypes.HANDLE]
+        handle = api.OpenProcess(0x100000, False, pid)
+        if not handle: return False
+        try: return api.WaitForSingleObject(handle, 0) == 258
+        finally: api.CloseHandle(handle)
+
+    def test_actual_download_merger_reports_progress_and_publishes_across_disks(self):
+        from yt_dlp import YoutubeDL
+        runtime = ROOT / ".runtime"
+        runtime.mkdir(exist_ok=True)
+        with tempfile.TemporaryDirectory(prefix="processing-test-", dir=runtime) as working, tempfile.TemporaryDirectory() as output:
+            work, destination = Path(working), Path(output)
+            video, audio = work / "video.mp4", work / "audio.m4a"
+            for inputs, target, codec in [(["-f", "lavfi", "-i", "testsrc2=size=160x90:rate=24"], video, ["-an", "-c:v", "libx264", "-preset", "ultrafast"]),
+                                           (["-f", "lavfi", "-i", "sine=frequency=440:sample_rate=48000"], audio, ["-vn", "-c:a", "aac"])]:
+                subprocess.run([tool("ffmpeg"), "-nostdin", "-v", "error", "-y", *inputs, "-t", "12", *codec, str(target)],
+                               creationflags=NO_WINDOW, stdin=subprocess.DEVNULL, check=True, timeout=30)
+            class Handler(SimpleHTTPRequestHandler):
+                def log_message(self, *args): pass
+            server = ThreadingHTTPServer(("127.0.0.1", 0), functools.partial(Handler, directory=str(work)))
+            threading.Thread(target=server.serve_forever, daemon=True).start()
+            events = []
+            origin = f"http://127.0.0.1:{server.server_port}/"
+            def extract(ydl, url, download=True):
+                return ydl.process_ie_result({"id": "jNQXAC9IVRw", "title": "Processing regression", "duration": 12,
+                    "webpage_url": "https://youtu.be/jNQXAC9IVRw", "extractor": "fixture", "extractor_key": "Fixture", "formats": [
+                    {"format_id": "137", "url": origin + "video.mp4", "ext": "mp4", "protocol": "http", "vcodec": "avc1", "acodec": "none", "height": 90, "width": 160, "fps": 24},
+                    {"format_id": "140", "url": origin + "audio.m4a", "ext": "m4a", "protocol": "http", "vcodec": "none", "acodec": "mp4a.40.2", "abr": 128}]}, download=download)
+            try:
+                with patch.object(YoutubeDL, "extract_info", extract), patch("host.worker.emit", side_effect=lambda kind, **data: events.append({"type": kind, **data})):
+                    result = globals()["download"]({"url": "https://youtu.be/jNQXAC9IVRw", "folder": str(destination),
+                        "workFolder": str(work), "mode": "video", "container": "mp4", "codec": "copy"}, [])
+            finally:
+                server.shutdown(); server.server_close()
+            saved = Path(result["path"])
+            self.assertEqual(saved.parent, destination.resolve())
+            self.assertEqual({s["codec_type"] for s in probe(saved)["streams"]}, {"video", "audio"})
+            self.assertTrue(any(e.get("stage") == "merging" and e.get("processedSeconds", 0) > 0 and e.get("written", 0) > 0 and e.get("percent") is not None for e in events), events)
+            self.assertTrue(any(e.get("stage") == "remuxing" and e.get("engine") == "copy" for e in events), events)
+            stages = [e.get("stage") for e in events if e.get("type") == "progress"]
+            self.assertLess(stages.index("merging"), stages.index("remuxing"))
+            self.assertNotIn("merging", stages[stages.index("remuxing"):])
+            if work.stat().st_dev != destination.stat().st_dev:
+                self.assertTrue(any(e.get("stage") == "saving" and e.get("copied", 0) > 0 for e in events), events)
+            self.assertFalse(list(work.glob(".ytdl-*")))
+            self.assertFalse(list(destination.glob(".ytdl-*")))
+            self.assertEqual(result["size"], saved.stat().st_size)
+
+
+if __name__ == "__main__": unittest.main()

tests/test_updates.py

@@ -0,0 +1,64 @@
+import hashlib
+import io
+import tempfile
+import unittest
+import zipfile
+from pathlib import Path
+from types import SimpleNamespace
+from unittest.mock import patch
+from host.main import NativeHost
+
+from host.updates import extract_zip, fetch, python_release, trusted_url
+
+
+class UpdateTests(unittest.TestCase):
+    def test_automatic_checks_wait_for_idle_and_respect_disabled_setting(self):
+        with tempfile.TemporaryDirectory() as temporary, patch("host.main.ROOT", Path(temporary)):
+            host = NativeHost(io.BytesIO())
+            try:
+                with patch("host.main.installation_root", return_value=Path(temporary)), patch.object(host, "schedule_updates"), \
+                     patch("host.updates.settings", return_value={"enabled": True}) as settings, patch("host.updates.due", return_value=True), \
+                     patch("host.updates.check_updates", return_value=[]) as check:
+                    host.jobs["video"] = {"status": "running"}
+                    host.auto_check(); check.assert_not_called()
+                    host.jobs.clear(); host.auto_check(); check.assert_called_once()
+                    settings.return_value = {"enabled": False}; check.reset_mock()
+                    host.auto_check(); check.assert_not_called()
+            finally: host.close()
+
+    def test_vendor_urls_and_archive_paths_are_restricted(self):
+        trusted_url("https://nodejs.org/dist/v24.21.0/node-v24.21.0-win-x64.zip")
+        for url in ("http://nodejs.org/file", "https://nodejs.org.evil.test/file", "https://name:secret@nodejs.org/file"):
+            with self.assertRaises(ValueError): trusted_url(url)
+        with tempfile.TemporaryDirectory() as temporary:
+            root = Path(temporary)
+            for name in ("../outside.exe", "C:/outside.exe", "runtime/../../outside.exe"):
+                archive = root / "bad.zip"
+                with zipfile.ZipFile(archive, "w") as package: package.writestr(name, b"bad")
+                with self.assertRaises(ValueError): extract_zip(archive, root / "component")
+            self.assertFalse((root / "outside.exe").exists())
+
+    def test_modified_download_is_rejected_before_use(self):
+        class Response:
+            headers = {"Content-Length": "8"}
+            def __enter__(self): return self
+            def __exit__(self, *args): return False
+            def iter_content(self, count): yield b"modified"
+        with tempfile.TemporaryDirectory() as temporary, patch("host.updates.get", return_value=Response()):
+            item = {"url": "https://nodejs.org/file", "sha256": hashlib.sha256(b"original").hexdigest()}
+            with self.assertRaisesRegex(ValueError, "Контрольная сумма"):
+                fetch(item, Path(temporary) / "download.zip", lambda _: None)
+
+    def test_python_uses_official_hash_and_stays_in_compatible_branch(self):
+        checksum = "a" * 64
+        index = '<a href="3.14.0/">3.14</a><a href="3.13.16/">16</a><a href="3.13.15/">15</a><a href="3.13.14/">14</a>'
+        def response(url):
+            if url.endswith("/ftp/python/"): return SimpleNamespace(text=index)
+            if "31316" in url: return SimpleNamespace(text="<tr><td>Source only</td></tr>")
+            return SimpleNamespace(text=f'<tr><td><a href="python-3.13.15-embed-amd64.zip">Windows embed</a></td><td><code>{checksum}</code></td></tr>')
+        with patch("host.updates.sys.version_info", SimpleNamespace(major=3, minor=13)), patch("host.updates.sys.version", "3.13.14"), patch("host.updates.get", side_effect=response):
+            result = python_release()
+        self.assertEqual(result["version"], "3.13.15"); self.assertEqual(result["sha256"], checksum)
+
+
+if __name__ == "__main__": unittest.main()

tests/thumbnail-placement.test.mjs

@@ -0,0 +1,139 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts = path.join(root, "test-artifacts");
+await fs.mkdir(artifacts, { recursive: true });
+const browser = await chromium.launch({ headless: true, executablePath: "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe" });
+const context = await browser.newContext({ viewport: { width: 1200, height: 800 }, reducedMotion: "reduce" });
+await context.addInitScript({ path: path.join(root, "tests/ui-fixture.js") });
+const poster = 'data:image/svg+xml,' + encodeURIComponent('<svg xmlns="http://www.w3.org/2000/svg" width="330" height="186"><defs><linearGradient id="g"><stop stop-color="#096574"/><stop offset="1" stop-color="#192636"/></linearGradient></defs><path fill="url(#g)" d="M0 0h330v186H0z"/></svg>');
+await context.route("https://www.youtube.com/**", route => route.fulfill({ contentType: "text/html", body: `<!doctype html><html dark><head><meta charset="utf-8"><style>
+body{margin:24px;background:#0f0f0f;color:#eee;font:16px/1.4 Arial}main{display:flex;gap:26px;align-items:flex-start}.card{display:block;width:330px;position:relative}a{color:inherit;text-decoration:none}img,video{display:block;width:100%;height:auto;aspect-ratio:330/186;object-fit:cover;border-radius:12px}a.title{display:block;font-weight:600;min-height:48px;margin-top:10px}.views{color:#aaa;margin-top:5px}ytd-thumbnail,yt-thumbnail-view-model{display:block}.short-image{display:block}.legacy-image{display:block;padding-bottom:28px}.modern-image{display:block;padding-bottom:20px}.scaled{transform:scale(.85);transform-origin:top left}.bordered{border:3px solid #333;padding:7px;box-sizing:border-box}
+</style></head><body><main>
+<ytm-shorts-lockup-view-model id="short-card" class="card"><a class="short-image" href="/shorts/Mf9GCn_LsUI"><yt-thumbnail-view-model><img src="${poster}" alt="Shorts preview"></yt-thumbnail-view-model></a><a class="title" href="/shorts/Mf9GCn_LsUI">ТЫ НЕ ВСТРЕЧАЛ этого Левиафана в Subnautica 2...</a><div class="views">1,6 млн просмотров</div></ytm-shorts-lockup-view-model>
+<div id="legacy-card" class="card"><ytd-thumbnail><a id="thumbnail" class="legacy-image" href="/watch?v=jNQXAC9IVRw"><img src="${poster}" alt="Video preview"></a></ytd-thumbnail><div class="title">S.T.A.L.K.E.R. — видео и описание</div></div>
+<yt-lockup-view-model id="modern-card" class="card scaled"><a class="yt-lockup-view-model__content-image modern-image" href="/watch?v=aircAruvnKk"><yt-thumbnail-view-model class="bordered"><img src="${poster}" alt="Modern preview"></yt-thumbnail-view-model><span>Название внутри ссылки</span></a><div class="views">Информация под превью</div></yt-lockup-view-model>
+</main></body></html>` }));
+const page = await context.newPage();
+const errors = []; page.on("pageerror", error => errors.push(error.message));
+
+async function assertInside(id) {
+  const geometry = await page.locator(`#${id}`).evaluate(card => {
+    const owner = card.dataset.ytdlPreview || card.querySelector('[data-ytdl-preview]')?.dataset.ytdlPreview;
+    const host = document.querySelector(`[data-ytdl-preview-for="${owner}"]`);
+    const media = card.querySelector('video, img');
+    const box = value => ({ left:value.left, top:value.top, right:value.right, bottom:value.bottom });
+    return { media: box(media.getBoundingClientRect()), buttons: [...host.shadowRoot.querySelectorAll('button')].map(button => box(button.getBoundingClientRect())), count: document.querySelectorAll(`[data-ytdl-preview-for="${owner}"]`).length };
+  });
+  assert.equal(geometry.count, 1, `Only one control pair in ${id}`);
+  for (const button of geometry.buttons) {
+    assert.ok(button.left >= geometry.media.left + 3 && button.right <= geometry.media.right - 3 && button.top >= geometry.media.top + 3 && button.bottom <= geometry.media.bottom - 3,
+      `Controls must stay inside ${id}'s actual picture: ${JSON.stringify(geometry)}`);
+  }
+}
+
+try {
+  await page.goto("https://www.youtube.com/");
+  await page.addScriptTag({ path: path.join(root, "extension/controls.js") });
+  for (const id of ["short-card", "legacy-card", "modern-card"]) {
+    await page.locator(`#${id} [data-ytdl-preview], #${id}[data-ytdl-preview]`).waitFor(); await assertInside(id);
+  }
+  // The real YouTube app is absolutely positioned: BODY has zero height, and
+  // its scroll/auto overflow is propagated to the viewport, not a zero-size clip.
+  await page.evaluate(() => {
+    document.querySelector('main').style.position='absolute';
+    document.body.style.overflowY='scroll'; document.body.style.overflowX='auto';
+  });
+  await page.waitForTimeout(100);
+  const shortOwner=await page.locator('#short-card').getAttribute('data-ytdl-preview');
+  assert.equal(await page.locator(`[data-ytdl-preview-for="${shortOwner}"]`).isVisible(),true,'Viewport overflow must not hide buttons when BODY has zero height');
+  await assertInside('short-card');
+  await page.screenshot({ path: path.join(artifacts, "thumbnail-placement.png"), animations: "disabled" });
+  await page.evaluate(() => {
+    const card = document.querySelector('#short-card');
+    card.addEventListener('mouseenter', () => {
+      const replacement = document.createElement('a'); replacement.href = '/shorts/Mf9GCn_LsUI'; replacement.className = 'short-image';
+      replacement.innerHTML = '<video style="background:#123b47"></video>';
+      card.querySelector('.short-image').replaceWith(replacement);
+      const player = document.createElement('div'); player.className = 'hover-player';
+      player.style.cssText = 'position:absolute;inset:0 0 auto;height:186px;background:#123b47;z-index:30;pointer-events:auto;border-radius:12px'; card.append(player);
+    }, { once:true });
+  });
+  await page.locator('#short-card').hover();
+  await page.locator('#short-card .hover-player').waitFor();
+  await page.waitForTimeout(250);
+  await assertInside('short-card');
+  const shortKey = await page.locator('#short-card').getAttribute('data-ytdl-preview');
+  const shortButtons = page.locator(`[data-ytdl-preview-for="${shortKey}"]`);
+  await shortButtons.locator('.download').click();
+  assert.equal(await page.evaluate(() => window.__quickRequests.at(-1)), 'https://www.youtube.com/watch?v=Mf9GCn_LsUI');
+  assert.equal(page.url(), 'https://www.youtube.com/');
+  await page.screenshot({ path: path.join(artifacts, 'thumbnail-hover-placement.png'), animations:'disabled' });
+  // YouTube can hide the original card while rendering its hover player in a
+  // separate overlay. Controls must be outside that opacity/visibility subtree.
+  await page.evaluate(() => document.querySelector('#short-card').style.opacity = '0');
+  assert.equal(await shortButtons.evaluate(host => host.parentElement === document.documentElement), true);
+  assert.equal(await shortButtons.locator('.download').evaluate(button => Number(getComputedStyle(button).opacity)), 1);
+  await shortButtons.locator('.download').click();
+  await page.evaluate(() => {
+    document.querySelector('#short-card').style.opacity = '';
+    document.querySelector('#short-card .short-image').style.visibility = 'hidden';
+  });
+  await page.waitForTimeout(250);
+  assert.equal(await shortButtons.isVisible(), true);
+  await shortButtons.locator('.download').click();
+  await page.evaluate(() => document.querySelector('#short-card .short-image').style.visibility = '');
+  // Hover playback can remove the entire image link, leaving only metadata and
+  // a separate player. That metadata must not move the controls into the title.
+  const beforeRemoval = await shortButtons.boundingBox();
+  await page.evaluate(() => {
+    const link = document.querySelector('#short-card .short-image');
+    window.__removedThumbnail = link; link.remove();
+  });
+  await page.waitForTimeout(250);
+  assert.deepEqual(await shortButtons.boundingBox(), beforeRemoval);
+  await shortButtons.locator('.download').click();
+  await page.evaluate(() => document.querySelector('#short-card').prepend(window.__removedThumbnail));
+  // Layout changes without a window resize: columns narrower, title grows,
+  // and a lazy image gets its final height after initial attachment.
+  await page.evaluate(() => {
+    for (const card of document.querySelectorAll('.card')) card.style.width = '260px';
+    document.querySelector('#short-card .title').style.minHeight = '110px';
+    document.querySelector('#short-card .hover-player').style.height = '146.5px';
+    document.querySelector('#legacy-card img').style.aspectRatio = '4/3';
+  });
+  await page.waitForTimeout(300);
+  for (const id of ['short-card','legacy-card','modern-card']) await assertInside(id);
+  await page.evaluate(() => {
+    document.querySelector('#short-card .short-image').href = '/shorts/jNQXAC9IVRw';
+    document.querySelector('#short-card .title').href = '/shorts/jNQXAC9IVRw';
+  });
+  await shortButtons.locator('.download').click();
+  assert.equal(await page.evaluate(() => window.__quickRequests.at(-1)), 'https://www.youtube.com/watch?v=jNQXAC9IVRw');
+  await page.evaluate(() => { document.body.style.minHeight = '1500px'; });
+  await page.setViewportSize({width:1200,height:300});
+  await page.evaluate(() => window.scrollTo(0,60));
+  await page.waitForTimeout(100);
+  await assertInside('short-card');
+  // A horizontally clipped Shorts shelf must not leave buttons floating over
+  // content outside the visible shelf.
+  await page.evaluate(() => {
+    const card = document.querySelector('#short-card');
+    const shelf = document.createElement('div'); shelf.id = 'short-shelf';
+    shelf.style.cssText = 'width:260px;overflow:hidden;flex-shrink:0';
+    card.before(shelf); shelf.append(card); card.style.marginLeft = '300px';
+  });
+  await page.waitForTimeout(100);
+  assert.equal(await shortButtons.isVisible(),false);
+  await page.evaluate(() => document.querySelector('#short-card').style.marginLeft='0');
+  await page.waitForTimeout(100);
+  assert.equal(await shortButtons.isVisible(),true);
+  await page.evaluate(() => document.querySelector('#short-card').remove());
+  await shortButtons.waitFor({state:'detached'});
+  assert.deepEqual(errors, []);
+  console.log('Thumbnail placement passed: real YouTube zero-height BODY, image bounds, title links, padding, borders, scaled layout, replaced/hidden/removed hover previews, responsive/lazy sizing, scroll, clipped shelves and recycled URLs.');
+} finally { await browser.close(); }

tests/ui-connection.test.mjs

@@ -0,0 +1,73 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { createUiConnection } from "../extension/ui-connection.js";
+
+function harness() {
+  const ports = [], events = [];
+  const runtime = { connect() {
+    const messages = [], disconnects = [];
+    const port = { sent: [], dead: false,
+      onMessage: { addListener: listener => messages.push(listener) },
+      onDisconnect: { addListener: listener => disconnects.push(listener) },
+      postMessage(message) {
+        if (this.dead) throw new Error("Attempting to use a disconnected port object");
+        this.sent.push(message);
+      },
+      respond(result, index = this.sent.length - 1) { messages.forEach(listener => listener({ id: this.sent[index].id, ok: true, result })); },
+      emit(message) { messages.forEach(listener => listener(message)); },
+      disconnect() { this.dead = true; disconnects.forEach(listener => listener()); },
+    };
+    ports.push(port); return port;
+  } };
+  const connection = createUiConnection({ runtime, onEvent: event => events.push(event), onDisconnect: () => events.push({ disconnected: true }) });
+  return { ...connection, ports, events, runtime };
+}
+
+test("a menu reconnects after worker shutdown, without resending an in-flight operation", async () => {
+  const h = harness();
+  const pending = h.call("helper_remove");
+  const rejected = assert.rejects(pending, /Связь с расширением прервана/);
+  const old = h.ports[0]; old.disconnect(); await rejected;
+  const next = h.call("helper_start");
+  assert.equal(h.ports.length, 2); assert.equal(old.sent.length, 1);
+  assert.equal(h.ports[1].sent[0].action, "helper_start");
+  h.ports[1].respond({ ready: true }); assert.deepEqual(await next, { ready: true });
+  // Late events from the old worker must not change the new status.
+  const count = h.events.length;
+  old.emit({ event: "helper", helper: { status: "missing" } }); old.disconnect();
+  assert.equal(h.events.length, count);
+  h.ports[1].emit({ event: "helper", helper: { status: "running" } });
+  assert.equal(h.events.at(-1).helper.status, "running");
+});
+
+test("a disconnected-port exception before its callback reconnects in the same click", async () => {
+  const h = harness();
+  const initial = h.call("hello"); h.ports[0].respond({ ready: true }); await initial;
+  h.ports[0].dead = true;
+  const retry = h.call("helper_start");
+  assert.equal(h.ports.length, 2);
+  h.ports[0].disconnect();
+  h.ports[1].respond({ ready: true }); assert.equal((await retry).ready, true);
+  assert.equal(h.ports[0].sent.length, 1, "Failed post was never delivered");
+});
+
+test("repeated disconnected-port failures stop after one retry with a readable error", async () => {
+  let attempts = 0;
+  const h = createUiConnection({ runtime: { connect() {
+    attempts++;
+    return { onMessage: { addListener() {} }, onDisconnect: { addListener() {} },
+      postMessage() { throw new Error("Attempting to use a disconnected port object"); } };
+  } } });
+  await assert.rejects(h.call("helper_start"), /Проверить подключение/);
+  assert.equal(attempts, 2);
+});
+
+test("helper errors are delivered once and do not replay updates or removal", async () => {
+  for (const action of ["helper_update", "helper_remove", "download"]) {
+    const h = harness(), result = h.call(action);
+    const rejected = assert.rejects(result, /Дождитесь завершения/);
+    h.ports[0].emit({ id: h.ports[0].sent[0].id, ok: false, error: "Дождитесь завершения загрузок" });
+    await rejected;
+    assert.equal(h.ports.length, 1); assert.equal(h.ports[0].sent.length, 1);
+  }
+});

tests/ui-fixture.js

@@ -0,0 +1,100 @@
+// Deterministic browser APIs for layout and interaction tests, without touching browser accounts.
+(() => {
+  const listeners = [];
+  const contentListeners = [];
+  const disconnectListeners = [];
+  let sessionEnabled = false;
+  const fixtureStorage = { preferences: {}, onboarding: { state: "complete", version: 1 } };
+  window.__fixtureStorage = fixtureStorage;
+  window.__downloadRequests = [];
+  window.__quickRequests = [];
+  window.__emitJob = job => {
+    fixtureStorage.jobs ||= {};
+    fixtureStorage.jobs[job.id] = job;
+    listeners.forEach(listener => listener({ event: "job", job: fixtureStorage.jobs[job.id] }));
+  };
+  window.__historyRequests = [];
+  window.__uiDisconnect = () => disconnectListeners.forEach(listener => listener());
+  window.__contentMessage = message => contentListeners.forEach(listener => listener(message));
+  let autoUpdate = true;
+  window.__updateRequests = [];
+  const hardware = () => ({ version: window.__helperVersion || "1.3.2", bundle: { mode: "autonomous", version: window.__helperVersion || "1.3.2", updateTogether: true }, supportsComponentUpdates: true, supportsWorkFolder: true, updateSettings: { enabled: autoUpdate },
+    gpu: window.__amdOnly ? "AMD Radeon RX 7900 XTX" : "NVIDIA GeForce RTX 5080", nvenc: window.__dependencyMissing || window.__amdOnly ? [] : ["h264", "hevc", "av1"],
+    amf: window.__amdOnly ? ["h264", "hevc", "av1"] : [], amf10bit: window.__amdOnly ? ["hevc", "av1"] : [], defaultFolder: "D:\\Videos", ready: !window.__dependencyMissing,
+    dependencies: ["python", "yt_dlp", "ejs", "node", "ffmpeg"].map(id => ({ id, status: window.__dependencyMissing && id === "ffmpeg" ? "missing" : "installed", version: "test-version" })) });
+  const metadata = { id: "aircAruvnKk", url: "https://www.youtube.com/watch?v=aircAruvnKk",
+    title: "But what is a neural network? | Deep learning chapter 1", channel: "3Blue1Brown", duration: 1148,
+    videos: [
+      { id: "401", height: 2160, fps: 60, codec: "av01.0.13M.08", extension: "mp4", hasAudio: false, size: 350000000, hdr: "SDR" },
+      { id: "137", height: 1080, fps: 30, codec: "avc1.640028", extension: "mp4", hasAudio: false, size: 100000000, hdr: "SDR" },
+      { id: "18", height: 360, fps: 30, codec: "avc1.42001E", extension: "mp4", hasAudio: true, size: 35000000, hdr: "SDR" },
+    ], audios: [{ id: "251", codec: "opus", extension: "webm", bitrate: 160, language: "en", note: "English", size: 5000000 }] };
+  window.chrome = {
+    runtime: {
+      getManifest: () => ({ version: window.__extensionVersion || "1.4.5" }),
+      getURL: file => `https://ui.ytdl.test/${file}`,
+      sendMessage: async message => {
+        if (message.type === "QUICK_DOWNLOAD") { window.__quickRequests.push(message.url); return { ok: true, jobId: "fixture-job" }; }
+        if (message.type === "CLOSE_MENU") parent.postMessage({ type: "FIXTURE_CLOSE_MENU" }, "https://www.youtube.com");
+        return { tabId: 42, jobs: [] };
+      },
+      onMessage: { addListener: listener => contentListeners.push(listener) },
+      connect: () => ({
+        onMessage: { addListener: listener => listeners.push(listener) },
+        onDisconnect: { addListener: listener => disconnectListeners.push(listener) },
+        postMessage: message => {
+          let result;
+          if ((message.action === "hello" || message.action === "helper_start") && window.__helperMissing) {
+            setTimeout(() => {
+              listeners.forEach(listener => listener({ event: "helper", helper: { status: "missing", message: "Помощник не установлен. Скачайте установщик." } }));
+              listeners.forEach(listener => listener({ id: message.id, ok: false, error: "Помощник не установлен." }));
+            }, 5);
+            return;
+          }
+          if (message.action === "hello" || message.action === "helper_start") result = hardware();
+          if (message.action === "helper_status") result = { status: "running", hardware: hardware() };
+          if (message.action === "update_settings") { autoUpdate = message.payload.enabled; result = { enabled: autoUpdate }; }
+          if (message.action === "helper_update") {
+            window.__updateRequests.push(message.payload); result = { jobId: "fixture-update" };
+            setTimeout(() => window.__emitJob({ id: "fixture-update", kind: "update", canCancel: false, title: "Обновление компонентов", status: "running", stage: "updating", percent: 36, message: "Скачиваю FFmpeg…" }), 10);
+          }
+          if (message.action === "dependency_install") {
+            result = { jobId: "fixture-dependency" };
+            setTimeout(() => {
+              window.__dependencyMissing = false;
+              listeners.forEach(listener => listener({ event: "helper", helper: { status: "running", hardware: hardware() } }));
+            }, 30);
+          }
+          if (message.action === "helper_remove") {
+            result = { removed: true };
+            listeners.forEach(listener => listener({ event: "helper", helper: { status: "missing", message: "Помощник удалён." } }));
+          }
+          if (message.action === "session_status") result = { status: sessionEnabled ? "connected" : "disabled", message: "Вход текущего браузера" };
+          if (message.action === "session_enable") { sessionEnabled = message.payload.enabled; result = { status: sessionEnabled ? "connected" : "disabled" }; }
+          if (message.action === "inspect") {
+            if (window.__requiresLogin && !sessionEnabled) {
+              setTimeout(() => listeners.forEach(listener => listener({id:message.id,ok:false,error:"ERROR: Sign in to confirm you’re not a bot. Use --cookies for authentication"})),5);
+              return;
+            }
+            result = metadata;
+          }
+          if (message.action === "pick_folder") result = { folder: "D:\\Videos\\YouTube" };
+          if (message.action === "open_history") { window.__historyRequests.push(message.payload); result = { opened: true }; }
+          if (message.action === "download") { window.__downloadRequests.push(message.payload); result = { jobId: "fixture-job" }; }
+          if (message.action === "state" || message.action === "jobs") result = { jobs: Object.values(fixtureStorage.jobs || {}) };
+          setTimeout(() => listeners.forEach(listener => listener({ id: message.id, ok: true, result })), 5);
+        },
+      }),
+    },
+    storage: { local: {
+      get: async keys => {
+        const data = { ...fixtureStorage };
+        if (window.__firstRun && !window.__onboardingStored) delete data.onboarding;
+        return Object.fromEntries((Array.isArray(keys) ? keys : [keys]).filter(key => key in data).map(key => [key, structuredClone(data[key])]));
+      },
+      set: async data => { Object.assign(fixtureStorage, structuredClone(data)); if (data.onboarding) window.__onboardingStored = true; },
+    } },
+    permissions: { request: async () => window.__denySessionPermission !== true },
+  };
+  window.__helperOffline = () => listeners.forEach(listener => listener({ event: "helper", helper: { status: "offline", message: "Помощник отключён." } }));
+})();

tests/ui.test.mjs

@@ -0,0 +1,239 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const artifacts = path.join(root, "test-artifacts");
+await fs.mkdir(artifacts, { recursive: true });
+const browser = await chromium.launch({ headless: true,
+  executablePath: process.env.YTDL_TEST_BROWSER || "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe" });
+const context = await browser.newContext({ viewport: { width: 1180, height: 860 }, reducedMotion: "reduce" });
+await context.addInitScript({ path: path.join(root, "tests/ui-fixture.js") });
+await context.route("**/*", async route => {
+  const url = new URL(route.request().url());
+  if (url.hostname === "ui.ytdl.test") {
+    const name = url.pathname.slice(1).split("/").pop();
+    if (!["downloader.html", "styles.css", "downloader.js", "onboarding.js", "ui-connection.js", "theme-init.js", "shared.js", "session.js"].includes(name)) return route.abort();
+    const type = name.endsWith(".html") ? "text/html" : name.endsWith(".css") ? "text/css" : "application/javascript";
+    return route.fulfill({ body: await fs.readFile(path.join(root, "extension", name)), contentType: type });
+  }
+  if (url.hostname === "www.youtube.com") return route.fulfill({ contentType: "text/html", body: `<!doctype html><html dark><head><meta charset="utf-8"><style>body{margin:0;background:#0f0f0f;color:#eee;font:14px "Segoe UI",sans-serif}main{width:780px;margin:35px}.player{height:330px;background:linear-gradient(135deg,#162c43,#0a1421);border-radius:15px;display:grid;place-items:center;color:#65849c;font-size:27px}h1{font-size:22px;margin:22px 0}#owner{display:flex;align-items:center;gap:9px}.channel{margin-right:12px}.channel b{display:block}.channel small{color:#999}#subscribe-button button{border:0;border-radius:22px;background:#eee;padding:11px 17px;color:#111;font-weight:600}.note{color:#8d98a6;margin-top:35px}.avatar{width:38px;height:38px;background:#577295;border-radius:50%}</style></head><body><main><div class="player">Deep learning · chapter 1</div><h1>But what is a neural network?</h1><ytd-watch-metadata><div id="owner"><span class="avatar"></span><span class="channel"><b>3Blue1Brown</b><small>Наглядная математика</small></span><div id="subscribe-button"><button>Подписаться</button></div></div></ytd-watch-metadata><p class="note">Тест интерфейса YouTubeDL</p></main></body></html>` });
+  return route.abort();
+});
+const page = await context.newPage();
+const errors = [];
+page.on("pageerror", error => errors.push(error.message));
+try {
+  await page.goto("https://www.youtube.com/watch?v=aircAruvnKk");
+  await page.addScriptTag({ path: path.join(root, "extension/controls.js") });
+  await page.addScriptTag({ path: path.join(root, "extension/content.js") });
+  await page.evaluate(() => window.addEventListener("message", event => {
+    if (event.origin === "https://ui.ytdl.test" && event.data?.type === "FIXTURE_CLOSE_MENU") window.__contentMessage({ type: "CLOSE_MENU" });
+  }));
+  assert.equal(await page.locator("#subscribe-button + #ytdl-subscribe-download").count(), 1, "Button must be next to Subscribe");
+  const siteDownload = page.locator("#ytdl-subscribe-download .download");
+  assert.equal(await siteDownload.locator("svg").count(), 1, "Keep the site download icon");
+  const beforeHover = await siteDownload.boundingBox();
+  await siteDownload.hover();
+  assert.deepEqual(await siteDownload.boundingBox(), beforeHover, "The site button must not move on hover");
+  await siteDownload.click();
+  assert.equal(await page.locator("#ytdl-menu").count(), 0, "Download starts directly without a choice menu");
+  assert.deepEqual(await page.evaluate(() => window.__quickRequests), ["https://www.youtube.com/watch?v=aircAruvnKk"]);
+  await page.locator("#ytdl-subscribe-download .settings").click();
+  const frame = page.frameLocator("#ytdl-menu iframe");
+  await frame.locator("#download-form").waitFor({ state: "visible" });
+  assert.equal(await frame.locator("#download svg").count(), 0);
+  assert.ok(!(await frame.locator("#download").textContent()).includes("↓"));
+  assert.equal(await frame.locator("#helper-status").textContent(), "Помощник работает");
+  assert.equal(await frame.locator('.dependency-row[data-status="installed"]').count(), 5);
+  assert.equal(await frame.locator("#quality option").count(), 4);
+  await frame.locator("#quality").selectOption("137");
+  const actionSizes = await frame.locator('.form-actions > button').evaluateAll(buttons => buttons.map(button => ({ width: button.getBoundingClientRect().width, height: button.getBoundingClientRect().height, font: getComputedStyle(button).fontSize })));
+  assert.ok(Math.abs(actionSizes[0].width - actionSizes[1].width) < 1);
+  assert.equal(actionSizes[0].height, actionSizes[1].height); assert.equal(actionSizes[0].font, actionSizes[1].font);
+  await frame.locator('.form-actions').screenshot({path:path.join(artifacts,'form-actions.png')});
+  await frame.locator('body').evaluate(() => window.__emitJob({ id: 'old-download', title: 'Сохранённый ролик', status: 'complete', stage: 'complete', result: {path:'D:/Videos/old.mp4'}, createdAt: 1 }));
+  assert.equal(await frame.locator('[data-job-id="old-download"]').count(), 0, 'Completed history moves to its own page');
+  await frame.locator('#open-history').click();
+  await frame.locator('body').evaluate(() => {
+    if (window.__historyRequests.length !== 1) throw new Error('History button must open a new tab');
+  });
+  await frame.locator('body').evaluate(() => window.__emitJob({id:'active-download',title:'Текущая загрузка',status:'running',stage:'downloading',percent:12,createdAt:2}));
+  assert.equal(await frame.locator('#active-jobs .job-card').isVisible(), true);
+  await frame.locator('body').evaluate(() => window.__emitJob({id:'active-download',title:'Текущая загрузка',status:'complete',stage:'complete',result:{path:'D:/Videos/new.mp4'},createdAt:2}));
+  assert.equal(await frame.locator('#active-jobs-section').isVisible(), false);
+  assert.equal(await frame.locator('#open-history').isVisible(), true);
+  await frame.locator("html[data-theme=dark]").waitFor();
+  await frame.locator("body").evaluate(() => { for (const animation of document.getAnimations()) if (Number.isFinite(animation.effect.getTiming().iterations)) animation.finish(); });
+  await page.screenshot({ path: path.join(artifacts, "menu-dark.png"), animations: "disabled" });
+  await frame.locator(".mode-switch label").filter({ hasText: /^Аудио$/ }).click();
+  assert.equal(await frame.locator("#video-options").isVisible(), false);
+  assert.equal(await frame.locator("#container option").count(), 5);
+  await frame.locator("#container").selectOption("mp3");
+  await frame.locator("#pick-folder").click();
+  await frame.locator("#pick-folder:not([disabled])").waitFor();
+  assert.equal(await frame.locator("#folder").inputValue(), "D:\\Videos\\YouTube");
+  await frame.locator("#download").click();
+  await page.locator("#ytdl-menu").waitFor({ state: "detached" });
+  const job = { id: "fixture-job", title: "But what is a neural network?", status: "running", stage: "encoding", engine: "nvenc", percent: 64, speed: "12.8x" };
+  await page.evaluate(job => window.__contentMessage({ type: "JOB_PROGRESS", job }), job);
+  await page.locator("#ytdl-notifications .toast").waitFor();
+  assert.match(await page.locator("#ytdl-notifications .stage").textContent(), /NVENC/);
+  await page.screenshot({ path: path.join(artifacts, "progress-toast.png"), animations: "disabled" });
+  await page.evaluate(() => { document.documentElement.removeAttribute("dark"); document.body.style.background = "#f9fafc"; document.body.style.color = "#182234"; });
+  await page.locator("#ytdl-notifications:not([dark])").waitFor();
+  await page.locator("#ytdl-subscribe-download .settings").click();
+  const lightFrame = page.frameLocator("#ytdl-menu iframe");
+  await lightFrame.locator("#download-form").waitFor({ state: "visible" });
+  assert.equal(await lightFrame.locator("html").getAttribute("data-theme"), "light");
+  await page.screenshot({ path: path.join(artifacts, "menu-light.png"), animations: "disabled" });
+  await page.setViewportSize({ width: 340, height: 720 });
+  const box = await page.locator("#ytdl-menu").boundingBox();
+  assert.ok(box.x >= 0 && box.x + box.width <= 340, "Menu must stay inside a narrow viewport");
+  await lightFrame.locator("#download-form").waitFor({ state: "visible" });
+  const overflow = await lightFrame.locator("html").evaluate(node => node.scrollWidth > node.clientWidth);
+  assert.equal(overflow, false, "No horizontal overflow");
+  await lightFrame.locator("html").evaluate(() => window.__helperOffline());
+  assert.equal(await lightFrame.locator("#helper-status").textContent(), "Помощник отключён");
+  assert.equal(await lightFrame.locator('.dependency-row[data-status="unknown"]').count(), 5);
+  await lightFrame.locator("#helper-start").click();
+  await lightFrame.locator("#download-form").waitFor({ state: "visible" });
+  assert.equal(await lightFrame.locator("#helper-status").textContent(), "Помощник работает");
+  await lightFrame.locator("#close").click();
+  await page.locator("#ytdl-menu").waitFor({ state: "detached" });
+  await page.evaluate(() => {
+    const thumbnail = document.createElement("ytd-thumbnail");
+    thumbnail.innerHTML = '<a id="thumbnail" href="/watch?v=jNQXAC9IVRw" style="display:block;width:260px;height:146px;background:#30506b"><img alt="Test video" style="width:100%;height:100%"></a>';
+    document.querySelector("main").prepend(thumbnail);
+  });
+  await page.locator(".ytdl-thumbnail-download .download").click();
+  assert.equal(page.url(), "https://www.youtube.com/watch?v=aircAruvnKk", "A thumbnail download must not navigate");
+  assert.equal(await page.evaluate(() => window.__quickRequests.at(-1)), "https://www.youtube.com/watch?v=jNQXAC9IVRw");
+  await page.locator(".ytdl-thumbnail-download .settings").click();
+  await page.frameLocator("#ytdl-menu iframe").locator("#download-form").waitFor({ state: "visible" });
+  assert.equal(new URL(await page.locator("#ytdl-menu iframe").getAttribute("src")).searchParams.get("url"), "https://www.youtube.com/watch?v=jNQXAC9IVRw");
+  await page.frameLocator('#ytdl-menu iframe').locator('#download-form').waitFor({state:'visible'});
+  await page.frameLocator('#ytdl-menu iframe').locator('#folder').press('Escape');
+  await page.locator('#ytdl-menu').waitFor({state:'detached'});
+  await page.evaluate(() => {
+    const preview = document.createElement('ytm-shorts-lockup-view-model');
+    preview.style.cssText='display:block;width:120px;height:230px;position:relative';
+    preview.innerHTML = '<a href="/shorts/Mf9GCn_LsUI" style="display:block;height:200px"><yt-thumbnail-view-model><img alt="Short" style="width:120px;height:200px"></yt-thumbnail-view-model></a>';
+    preview.addEventListener('mouseenter', () => {
+      const replacement=document.createElement('a'); replacement.href='/shorts/Mf9GCn_LsUI'; replacement.style.cssText='display:block;height:200px';
+      replacement.innerHTML='<video style="width:120px;height:200px;background:#24364c"></video>';
+      preview.querySelector('a').replaceWith(replacement);
+      const player=document.createElement('div'); player.className='hover-player'; player.style.cssText='position:absolute;inset:0 0 30px;z-index:30;background:#24364c'; preview.append(player);
+    }, {once:true});
+    document.querySelector('main').prepend(preview);
+  });
+  await page.locator('ytm-shorts-lockup-view-model[data-ytdl-preview]').waitFor();
+  await page.locator('ytm-shorts-lockup-view-model').hover();
+  await page.locator('ytm-shorts-lockup-view-model .hover-player').waitFor();
+  const shortKey=await page.locator('ytm-shorts-lockup-view-model').getAttribute('data-ytdl-preview');
+  const shortButtons=page.locator(`[data-ytdl-preview-for="${shortKey}"]`);
+  assert.equal(await shortButtons.evaluate(node => node.parentElement === document.documentElement), true);
+  await shortButtons.locator('.download').click();
+  assert.equal(await page.evaluate(() => window.__quickRequests.at(-1)), 'https://www.youtube.com/watch?v=Mf9GCn_LsUI');
+  await shortButtons.locator('.settings').click();
+  await page.frameLocator('#ytdl-menu iframe').locator('#download-form').waitFor({state:'visible'});
+  await page.frameLocator('#ytdl-menu iframe').locator('#close').click();
+  await page.locator('#ytdl-menu').waitFor({state:'detached'});
+  await page.evaluate(() => {
+    history.pushState({}, "", "/shorts/jNQXAC9IVRw");
+    document.body.innerHTML = '<ytd-shorts><ytd-reel-video-renderer is-active><div id="actions" style="position:fixed;right:20px;bottom:180px"></div></ytd-reel-video-renderer></ytd-shorts>';
+    document.dispatchEvent(new Event("yt-navigate-finish"));
+  });
+  await page.locator("#actions #ytdl-shorts-download .download").click();
+  assert.equal(await page.evaluate(() => window.__quickRequests.at(-1)), "https://www.youtube.com/watch?v=jNQXAC9IVRw");
+  await page.locator("#ytdl-shorts-download .settings").click();
+  await page.frameLocator("#ytdl-menu iframe").locator("#download-form").waitFor({ state: "visible" });
+  await page.screenshot({ path: path.join(artifacts, "shorts-settings.png"), animations: "disabled" });
+  await page.evaluate(() => window.__contentMessage({ type: 'JOB_PROGRESS', job: {
+    id: 'component-complete', title: 'FFmpeg', kind: 'dependency', stage: 'complete', status: 'complete', percent: 100, result: { title: 'FFmpeg' }
+  } }));
+  assert.equal(await page.locator('#ytdl-notifications [data-id="component-complete"] .action').isVisible(), false);
+  const components = await context.newPage();
+  await components.addInitScript(() => { window.__dependencyMissing = true; });
+  await components.goto('https://ui.ytdl.test/downloader.html?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DjNQXAC9IVRw');
+  if (!await components.locator('#helper-panel').evaluate(panel => panel.open)) await components.locator('#helper-panel > summary').click();
+  await components.locator('.dependencies summary').click();
+  await components.locator('.dependency-row[data-dependency="ffmpeg"][data-status="missing"]').waitFor();
+  assert.equal(await components.locator('#download-form').isVisible(), false);
+  assert.equal(await components.locator('#engine option[value="nvenc"]').isDisabled(), true);
+  assert.equal(await components.locator('.dependency-row button').count(), 0);
+  assert.equal(await components.locator('#helper-install').textContent(), 'Восстановить');
+  assert.equal(await components.locator('#helper-install').getAttribute('href'), 'https://git.lonarpgproxy.space/OwnerLink/YouTubeDL/releases/latest');
+  assert.equal(await components.locator('#helper-install').getAttribute('target'), '_blank');
+  assert.equal(await components.locator('#helper-install').getAttribute('download'), null);
+  // A repaired bundle reports new capabilities after the helper restarts.
+  await components.evaluate(() => { window.__dependencyMissing = false; });
+  await components.locator('#helper-start').click();
+  await components.locator('#download-form').waitFor({state:'visible'});
+  assert.equal(await components.locator('.dependency-row[data-status="installed"]').count(), 5);
+  assert.equal(await components.locator('#engine option[value="nvenc"]').isDisabled(), false);
+  await components.close();
+  const amdPage=await context.newPage();
+  await amdPage.addInitScript(() => { window.__amdOnly=true; });
+  await amdPage.goto('https://ui.ytdl.test/downloader.html?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DjNQXAC9IVRw');
+  await amdPage.locator('#download-form').waitFor({state:'visible'});
+  assert.equal(await amdPage.locator('#engine option[value="nvenc"]').isDisabled(),true);
+  assert.equal(await amdPage.locator('#engine option[value="amf"]').isDisabled(),false);
+  await amdPage.locator('.advanced summary').click();
+  await amdPage.locator('#codec').selectOption('hevc'); await amdPage.locator('#engine').selectOption('amf');
+  assert.match(await amdPage.locator('#processing-hint').textContent(),/AMD AMF/);
+  await amdPage.locator('#codec').selectOption('vp9');
+  assert.match(await amdPage.locator('#processing-hint').textContent(),/недоступен/);
+  assert.equal(await amdPage.locator('#download').isDisabled(),true);
+  await amdPage.locator('#codec').selectOption('hevc');
+  assert.equal(await amdPage.locator('#download').isDisabled(),false);
+  await amdPage.locator('#helper-panel > summary').click();
+  assert.equal(await amdPage.locator('#helper-install').textContent(),'Переустановить');
+  await amdPage.locator('#auto-update').uncheck();
+  await amdPage.locator('#helper-update').click();
+  await amdPage.locator('#active-jobs .job-stage').filter({hasText:'Скачиваю FFmpeg'}).waitFor();
+  assert.equal(await amdPage.locator('#helper-update').isDisabled(),true);
+  assert.equal(await amdPage.evaluate(() => window.__updateRequests.length),1);
+  await amdPage.evaluate(() => window.__emitJob({id:'fixture-update',kind:'update',canCancel:false,status:'complete',stage:'complete',result:{title:'Все компоненты актуальны'}}));
+  await amdPage.locator('#helper-update:not([disabled])').waitFor();
+  assert.equal(await amdPage.locator('#active-jobs-section').isVisible(),false,'Completed component updates leave the active list');
+  assert.match(await amdPage.locator('#update-note').textContent(),/актуальны/);
+  await amdPage.close();
+  const loginPage = await context.newPage();
+  await loginPage.addInitScript(() => { window.__requiresLogin = true; window.__denySessionPermission = true; });
+  await loginPage.goto('https://ui.ytdl.test/downloader.html?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DjNQXAC9IVRw&theme=dark');
+  await loginPage.locator('#alert:not([hidden])').waitFor();
+  assert.equal(await loginPage.locator('#helper-status').textContent(), 'Помощник работает');
+  assert.equal(await loginPage.locator('#video-title').textContent(), 'Не удалось получить качество');
+  assert.match(await loginPage.locator('#alert').textContent(), /Использовать вход в YouTube/);
+  assert.ok(!(await loginPage.locator('#alert').textContent()).includes('cookies-from-browser'));
+  await loginPage.locator('#session-enable').click();
+  assert.match(await loginPage.locator('#alert').textContent(), /не разрешён/);
+  await loginPage.evaluate(() => { window.__denySessionPermission = false; });
+  await loginPage.locator('#session-enable').click();
+  await loginPage.locator('#download-form').waitFor({state:'visible'});
+  assert.equal(await loginPage.locator('#session-status').textContent(), 'Вход браузера подключён');
+  assert.equal(await loginPage.locator('#alert').isVisible(), false);
+  await loginPage.screenshot({path:path.join(artifacts,'session-connected.png'),animations:'disabled'});
+  await loginPage.locator('#session-disable').click();
+  await loginPage.locator('#session-panel[data-state="disabled"]').waitFor();
+  assert.equal(await loginPage.locator('#session-status').textContent(), 'Вход в YouTube не подключён');
+  await loginPage.close();
+  const storagePage = await context.newPage();
+  await storagePage.goto('https://ui.ytdl.test/downloader.html?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DjNQXAC9IVRw&theme=dark');
+  await storagePage.locator('#download-form').waitFor({state:'visible'});
+  await storagePage.locator('#folder').fill('C:\\Finished');
+  await storagePage.locator('#pick-work-folder').click();
+  await storagePage.waitForFunction(() => window.__fixtureStorage.preferences.workFolder === 'D:\\Videos\\YouTube');
+  assert.equal(await storagePage.locator('#folder').inputValue(), 'C:\\Finished');
+  await storagePage.locator('#download').click();
+  await storagePage.waitForFunction(() => window.__downloadRequests.length === 1);
+  const storageRequest = await storagePage.evaluate(() => window.__downloadRequests[0]);
+  assert.equal(storageRequest.folder, 'C:\\Finished');
+  assert.equal(storageRequest.workFolder, 'D:\\Videos\\YouTube');
+  await storagePage.close();
+  assert.deepEqual(errors, []);
+  console.log("UI checks passed: direct download + settings, stationary buttons, thumbnails, Shorts, real-state indicators, reconnect, themes and narrow layout.");
+} finally { await browser.close(); }

tests/version-compatibility.test.mjs

@@ -0,0 +1,62 @@
+import assert from "node:assert/strict";
+import fs from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const browser = await chromium.launch({ headless: true, executablePath: "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe" });
+const context = await browser.newContext({ viewport: { width: 360, height: 900 }, reducedMotion: "reduce" });
+await context.addInitScript({ path: path.join(root, "tests/ui-fixture.js") });
+await context.addInitScript(() => { window.__helperVersion = "1.3.0"; });
+await context.route("https://ui.ytdl.test/**", async route => {
+  const name = new URL(route.request().url()).pathname.slice(1);
+  if (!["downloader.html", "downloader.js", "onboarding.js", "ui-connection.js", "theme-init.js", "styles.css", "shared.js", "session.js"].includes(name)) return route.abort();
+  return route.fulfill({ body: await fs.readFile(path.join(root, "extension", name)), contentType: name.endsWith(".html") ? "text/html" : name.endsWith(".css") ? "text/css" : "application/javascript" });
+});
+try {
+  const page = await context.newPage();
+  const errors = [];
+  page.on("pageerror", error => errors.push(error.message));
+  await page.goto("https://ui.ytdl.test/downloader.html?theme=dark&url=https://www.youtube.com/watch?v=aircAruvnKk");
+  await page.locator('#helper-panel[data-state="incompatible"]').waitFor();
+  assert.match(await page.locator('#helper-message').textContent(), /1\.3\.0.*1\.4\.5/);
+  assert.match(await page.locator('#helper-versions').textContent(), /Расширение 1\.4\.5.*Помощник 1\.3\.0/);
+  assert.equal(await page.locator('#helper-install').textContent(), 'Обновить помощник');
+  assert.equal(await page.locator('#download').isDisabled(), true);
+  assert.equal(await page.locator('#download-form').isVisible(), false);
+  await page.locator('#open-setup').click();
+  await page.locator('#setup-next').click();
+  await page.locator('#setup-helper[data-state="incompatible"]').waitFor();
+  assert.equal(await page.locator('#setup-next').isDisabled(), true);
+  assert.equal(await page.locator('#setup-install').textContent(), 'Обновить помощник');
+  assert.match(await page.locator('#setup-versions').textContent(), /1\.4\.5.*1\.3\.0/);
+  await page.evaluate(() => { window.__helperVersion = '1.3.2'; });
+  await page.locator('#setup-check').click();
+  await page.locator('#setup-helper[data-state="running"]').waitFor();
+  assert.match(await page.locator('#setup-versions').textContent(), /Версии совместимы/);
+  await page.locator('#setup-next:not([disabled])').waitFor();
+  await page.evaluate(() => { window.__helperVersion = '1.3.3'; });
+  await page.locator('#setup-check').click();
+  await page.locator('#setup-helper[data-state="incompatible"]').waitFor();
+  assert.equal(await page.locator('#setup-next').isDisabled(), true);
+  assert.equal(await page.locator('#setup-install').textContent(), 'Обновить расширение');
+  assert.equal(await page.locator('#setup-install-steps').isVisible(), false);
+  await page.locator('#setup-close').click();
+  assert.equal(await page.locator('#helper-install').textContent(), 'Обновить расширение');
+  assert.match(await page.locator('#helper-message').textContent(), /Помощник 1\.3\.3.*расширением 1\.4\.5/);
+  assert.equal(await page.locator('#download').isDisabled(), true);
+  await page.evaluate(() => { window.__helperVersion = '1.3.2'; });
+  await page.locator('#helper-start').click();
+  await page.locator('#helper-panel[data-state="running"]').waitFor();
+  await page.locator('#download:not([disabled])').waitFor();
+  assert.match(await page.locator('#helper-versions').textContent(), /Версии совместимы/);
+  assert.equal(await page.evaluate(() => document.documentElement.scrollWidth <= innerWidth), true);
+  await fs.mkdir(path.join(root, 'test-artifacts'), { recursive: true });
+  await page.screenshot({ path: path.join(root, 'test-artifacts/version-compatibility-360.png'), animations: 'disabled' });
+  assert.deepEqual(errors, []);
+  console.log('Version UI passed in Edge: both update directions, versions shown in settings and first-run wizard, downloads blocked until compatible, recovery without reload, 360px layout.');
+} finally {
+  await context.close();
+  await browser.close();
+}

tools/build.py

@@ -0,0 +1,50 @@
+"""Build the small extension archive; the Windows helper is distributed separately."""
+import binascii
+import json
+import struct
+import zlib
+import zipfile
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+
+
+def png_chunk(kind, data):
+    return struct.pack(">I", len(data)) + kind + data + struct.pack(">I", binascii.crc32(kind + data) & 0xffffffff)
+
+
+def icon(size):
+    rows = bytearray()
+    for y in range(size):
+        rows.append(0)
+        for x in range(size):
+            u, v = (x + 0.5) / size, (y + 0.5) / size
+            dx, dy = max(0.18 - u, 0, u - 0.82), max(0.18 - v, 0, v - 0.82)
+            alpha = 255 if dx * dx + dy * dy < 0.18 ** 2 else 0
+            color = (int(74 - 47 * v), int(205 - 52 * v), int(243 - 32 * v), alpha)
+            stem = 0.44 < u < 0.56 and 0.22 < v < 0.60
+            arrow = 0.46 < v < 0.71 and abs(u - 0.5) < (0.71 - v) * 1.15
+            tray = (0.26 < u < 0.74 and 0.76 < v < 0.82) or (0.26 < u < 0.32 or 0.68 < u < 0.74) and 0.66 < v < 0.82
+            if stem or arrow or tray: color = (8, 39, 57, alpha)
+            rows.extend(color)
+    return b"\x89PNG\r\n\x1a\n" + png_chunk(b"IHDR", struct.pack(">IIBBBBB", size, size, 8, 6, 0, 0, 0)) + png_chunk(b"IDAT", zlib.compress(bytes(rows))) + png_chunk(b"IEND", b"")
+
+
+def main():
+    icons = ROOT / "extension" / "icons"
+    icons.mkdir(exist_ok=True)
+    for size in (16, 32, 48, 128): (icons / f"{size}.png").write_bytes(icon(size))
+    (ROOT / "dist").mkdir(exist_ok=True)
+    version = json.loads((ROOT / "extension" / "manifest.json").read_text(encoding="utf-8"))["version"]
+    destination = ROOT / "dist" / f"YouTubeDL-{version}.zip"
+    with zipfile.ZipFile(destination, "w", compression=zipfile.ZIP_DEFLATED) as archive:
+        for path in (ROOT / "extension").rglob("*"):
+            if path.is_file() and path.suffix.lower() != ".exe" and "__pycache__" not in path.parts:
+                archive.write(path, str(path.relative_to(ROOT)))
+        for name in ("INSTALL.md", "LICENSE", "PRIVACY.md", "THIRD_PARTY.md"):
+            path = ROOT / name
+            if path.is_file(): archive.write(path, name)
+    print(destination)
+
+
+if __name__ == "__main__": main()

tools/build_bundle.py

@@ -0,0 +1,172 @@
+"""Build the offline Windows x64 installer with only the system C# compiler.
+
+Build-time downloads are cached and recorded. The resulting installer has no
+network code, pip, or dependency on tools installed on the recipient's machine.
+"""
+from __future__ import annotations
+import argparse
+import concurrent.futures
+import hashlib
+import json
+import os
+import shutil
+import subprocess
+import sys
+import urllib.request
+import zipfile
+from pathlib import Path
+import requests
+
+ROOT = Path(__file__).resolve().parent.parent
+CACHE = ROOT / ".build-cache"
+BUILD = ROOT / ".build"
+KIT = BUILD / "kit"
+PYTHON = "3.13.14"
+PYTHON_SHA256 = "90b4e5b9898b72d744650524bff92377c367f44bd5fbd09e3148656c080ad907"
+NODE = "v24.21.0"
+FFMPEG_ARCHIVE = "ffmpeg-master-latest-win64-gpl-shared.zip"
+FFMPEG_SHA256 = "eb7afd4ecced72ab7d5d6fdd36dbc359173aa2daf6081817f7b678345898838b"
+
+
+def digest(path):
+    value = hashlib.sha256()
+    with path.open("rb") as stream:
+        for chunk in iter(lambda: stream.read(1024 * 1024), b""):
+            value.update(chunk)
+    return value.hexdigest()
+
+
+def fetch(url, name, expected=None):
+    destination = CACHE / name
+    if not destination.is_file():
+        print(f"Downloading {name}", flush=True)
+        partial = destination.with_suffix(destination.suffix + ".partial")
+        with requests.get(url, stream=True, timeout=90) as source, partial.open("wb") as output:
+            source.raise_for_status()
+            for chunk in source.iter_content(1024 * 1024): output.write(chunk)
+        partial.replace(destination)
+    actual = digest(destination)
+    if expected and actual != expected:
+        raise ValueError(f"Checksum mismatch: {name}")
+    return {"url": url, "file": name, "sha256": actual}
+
+
+def safe_extract(archive, destination):
+    root = destination.resolve()
+    with zipfile.ZipFile(archive) as package:
+        for item in package.infolist():
+            candidate = (root / item.filename).resolve()
+            if root not in candidate.parents and candidate != root:
+                raise ValueError("Unsafe archive path")
+            package.extract(item, root)
+
+
+def prepare():
+    CACHE.mkdir(exist_ok=True); BUILD.mkdir(exist_ok=True)
+    if KIT.exists():
+        if KIT.resolve().parent != BUILD.resolve() or KIT.is_symlink():
+            raise ValueError("Unsafe build cleanup path")
+        shutil.rmtree(KIT)
+    KIT.mkdir()
+    sources = [
+        (f"https://www.python.org/ftp/python/{PYTHON}/python-{PYTHON}-embed-amd64.zip", "python.zip", PYTHON_SHA256),
+        (f"https://nodejs.org/dist/{NODE}/node-{NODE}-win-x64.zip", "node.zip", None),
+        (f"https://github.com/yt-dlp/FFmpeg-Builds/releases/download/latest/{FFMPEG_ARCHIVE}", FFMPEG_ARCHIVE, FFMPEG_SHA256),
+    ]
+    # Node publishes a SHA256 manifest for every official release.
+    response = requests.get(f"https://nodejs.org/dist/{NODE}/SHASUMS256.txt", timeout=30); response.raise_for_status()
+    checksums = response.text
+    node_hash = next(line.split()[0] for line in checksums.splitlines() if line.endswith(f"node-{NODE}-win-x64.zip"))
+    sources[1] = (*sources[1][:2], node_hash)
+    with concurrent.futures.ThreadPoolExecutor(max_workers=3) as executor:
+        records = list(executor.map(lambda item: fetch(*item), sources))
+    python = KIT / "runtime" / "python"
+    python.mkdir(parents=True)
+    safe_extract(CACHE / "python.zip", python)
+    (python / "python313._pth").write_text("python313.zip\n.\nLib/site-packages\n../../\nimport site\n", encoding="ascii")
+    # Verify the signed Python executable after extracting the official ZIP.
+    verifier = os.environ.get("YTDL_BUILD_POWERSHELL") or "powershell.exe"
+    signature = subprocess.check_output([verifier, "-NoProfile", "-ExecutionPolicy", "Bypass", "-Command",
+        "$taskSignature=Get-AuthenticodeSignature -LiteralPath $env:YTDL_VERIFY_PYTHON; Write-Output $taskSignature.Status"],
+        env={**os.environ, "YTDL_VERIFY_PYTHON": str(python / "python.exe")}, text=True).strip()
+    if signature != "Valid":
+        raise ValueError("Embedded Python signature verification failed: " + signature)
+    binary = KIT / "runtime" / "bin"; binary.mkdir()
+    licenses = KIT / "licenses"; licenses.mkdir()
+    with zipfile.ZipFile(CACHE / "node.zip") as package:
+        for name in ("node.exe", "LICENSE"):
+            item = next(entry for entry in package.namelist() if entry.endswith("/" + name))
+            (binary / name if name.endswith(".exe") else licenses / "Node-LICENSE.txt").write_bytes(package.read(item))
+    with zipfile.ZipFile(CACHE / FFMPEG_ARCHIVE) as package:
+        for item in package.namelist():
+            name = Path(item).name
+            if "/bin/" in item and (name.endswith(".dll") or name in {"ffmpeg.exe", "ffprobe.exe"}):
+                (binary / name).write_bytes(package.read(item))
+            elif name == "LICENSE.txt":
+                (licenses / "FFmpeg-LICENSE.txt").write_bytes(package.read(item))
+    wheels = CACHE / "wheels"; wheels.mkdir(exist_ok=True)
+    options = ["--platform", "win_amd64", "--python-version", "3.13", "--implementation", "cp",
+               "--abi", "cp313", "--abi", "abi3", "--abi", "none", "--only-binary", ":all:"]
+    requirement = "yt-dlp[default]==2026.8.19"
+    subprocess.run([sys.executable, "-m", "pip", "download", "--disable-pip-version-check", "-d", str(wheels), *options, requirement], check=True)
+    subprocess.run([sys.executable, "-m", "pip", "install", "--disable-pip-version-check", "--no-index", "--find-links", str(wheels),
+                    "--target", str(python / "Lib" / "site-packages"), "--no-compile", "--ignore-requires-python", *options, requirement], check=True)
+    (licenses / "THIRD-PARTY.txt").write_text(
+        "Python: https://www.python.org/ ; license: runtime/python/LICENSE.txt\n"
+        "Node.js: https://nodejs.org/ ; license: Node-LICENSE.txt\n"
+        "FFmpeg Windows build and corresponding source/build instructions: https://github.com/yt-dlp/FFmpeg-Builds ; GPL license: FFmpeg-LICENSE.txt\n"
+        "yt-dlp and Python libraries: runtime/python/Lib/site-packages/*.dist-info (licenses and metadata)\n"
+        "yt-dlp source: https://github.com/yt-dlp/yt-dlp/tree/2026.08.19\n", encoding="utf-8")
+    (BUILD / "sources.json").write_text(json.dumps(records, indent=2), encoding="utf-8")
+
+
+def build():
+    if not KIT.is_dir():
+        raise ValueError("Run with --prepare first.")
+    scripts = KIT / "runtime/python/Lib/site-packages/bin"
+    if scripts.exists():
+        if KIT.resolve() not in scripts.resolve().parents or scripts.is_symlink():
+            raise ValueError("Unsafe console-script cleanup path")
+        # pip's generated EXE launchers refer to the build interpreter. The helper
+        # imports these libraries directly, so no console launchers are shipped.
+        shutil.rmtree(scripts)
+    shutil.copytree(ROOT / "host", KIT / "host", dirs_exist_ok=True, ignore=shutil.ignore_patterns("__pycache__", "*.pyc"))
+    sys.path.insert(0, str(ROOT))
+    from host.common import VERSION
+    version = VERSION
+    metadata = {"product": "YouTubeDL.Helper", "mode": "autonomous", "version": version, "platform": "windows-x64",
+                "tools": {"python": "runtime/python/python.exe", "node": "runtime/bin/node.exe", "ffmpeg": "runtime/bin/ffmpeg.exe", "ffprobe": "runtime/bin/ffprobe.exe"},
+                "sources": json.loads((BUILD / "sources.json").read_text(encoding="utf-8"))}
+    (KIT / "bundle.json").write_text(json.dumps(metadata, indent=2), encoding="utf-8")
+    environment = {**os.environ, "PATH": str(Path(os.environ.get("SystemRoot", r"C:\Windows")) / "System32"),
+                   "PYTHONPATH": "C:/NONEXISTENT", "PYTHONHOME": "C:/NONEXISTENT", "PYTHONNOUSERSITE": "1"}
+    subprocess.run([str(KIT / "runtime/python/python.exe"), "-I", "-B", "-m", "host.bootstrap", "verify"], env=environment, check=True)
+    files = {str(path.relative_to(KIT)).replace("\\", "/"): digest(path) for path in KIT.rglob("*") if path.is_file() and path.name != "bundle-files.json"}
+    (KIT / "bundle-files.json").write_text(json.dumps(files, indent=2), encoding="utf-8")
+    archive = BUILD / "bundle.zip"
+    with zipfile.ZipFile(archive, "w", zipfile.ZIP_DEFLATED, compresslevel=6) as package:
+        for file in KIT.rglob("*"):
+            if file.is_file(): package.write(file, str(file.relative_to(KIT)))
+    code = (ROOT / "tools" / "setup.cs").read_text(encoding="utf-8").replace("@BUNDLE_VERSION@", version).replace("@BUNDLE_HASH@", digest(archive))
+    source = BUILD / "setup.cs"; source.write_text(code, encoding="utf-8-sig")
+    compiler = Path(os.environ.get("SystemRoot", r"C:\Windows")) / "Microsoft.NET/Framework64/v4.0.30319/csc.exe"
+    common = [str(compiler), "/nologo", "/target:winexe", "/platform:x64", "/optimize+", "/r:System.Windows.Forms.dll",
+              "/r:System.Drawing.dll", "/r:System.IO.Compression.dll", "/r:System.IO.Compression.FileSystem.dll", "/r:System.Web.Extensions.dll",
+              f"/win32manifest:{ROOT / 'tools/setup.manifest'}"]
+    manager = BUILD / "YouTubeDL-Manager.exe"
+    subprocess.run([*common, f"/out:{manager}", str(source)], check=True)
+    (ROOT / "dist").mkdir(exist_ok=True)
+    installer = ROOT / "dist/YouTubeDL-Helper-Setup.exe"
+    subprocess.run([*common, "/define:SETUP", f"/resource:{archive},bundle.zip", f"/resource:{manager},manager.exe", f"/out:{installer}", str(source)], check=True)
+    destination = ROOT / "dist" / f"YouTubeDL-Helper-{version}-Setup.exe"
+    shutil.copy2(installer, destination)
+    (ROOT / "dist" / f"YouTubeDL-Helper-{version}-manifest.json").write_text(json.dumps({**metadata, "installerSHA256": digest(installer),
+        "installerBytes": installer.stat().st_size, "bundleSHA256": digest(archive)}, indent=2), encoding="utf-8")
+    print(f"Offline installer built: {destination} ({installer.stat().st_size / 1024**2:.1f} MiB)", flush=True)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(); parser.add_argument("--prepare", action="store_true"); parser.add_argument("--prepare-only", action="store_true")
+    args = parser.parse_args()
+    if args.prepare or args.prepare_only: prepare()
+    if not args.prepare_only: build()

tools/capture-site-ui.mjs

@@ -0,0 +1,27 @@
+// Capture the real extension renderer with the existing deterministic fixture.
+// This never opens a personal browser profile or accesses real cookies.
+import fs from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+const root = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+const browser = await chromium.launch({ headless: true, executablePath: process.env.YTDL_TEST_BROWSER || "C:/Program Files (x86)/Microsoft/Edge/Application/msedge.exe" });
+try {
+  const context = await browser.newContext({ viewport: { width: 520, height: 1080 }, reducedMotion: "reduce" });
+  await context.addInitScript({ path: path.join(root, "tests/ui-fixture.js") });
+  await context.route("**/*", async route => {
+    const url = new URL(route.request().url());
+    const name = path.basename(url.pathname);
+    if (url.hostname !== "ui.ytdl.test" || !["downloader.html", "downloader.js", "onboarding.js", "ui-connection.js", "theme-init.js", "styles.css", "shared.js", "session.js"].includes(name)) return route.abort();
+    return route.fulfill({ body: await fs.readFile(path.join(root,"extension",name)), contentType: name.endsWith(".html") ? "text/html" : name.endsWith(".css") ? "text/css" : "application/javascript" });
+  });
+  const page = await context.newPage();
+  await fs.mkdir(path.join(root,"site/assets"),{recursive:true});
+  for (const theme of ["dark","light"]) {
+    await page.goto(`https://ui.ytdl.test/downloader.html?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DaircAruvnKk&theme=${theme}`);
+    await page.locator("#download-form").waitFor({state:"visible"});
+    await page.locator("#quality").selectOption("137");
+    await page.locator("#folder").fill("C:\\Videos");
+    await page.locator(".app").screenshot({path:path.join(root,`site/assets/menu-${theme}.png`),animations:"disabled"});
+  }
+} finally { await browser.close(); }

tools/collect_release_materials.py

@@ -0,0 +1,86 @@
+"""Publish license texts and pinned upstream source materials alongside the helper.
+
+Run after tools/build_bundle.py. This does not alter or install the helper.
+Third-party FFmpeg dependency download/build recipes are preserved verbatim.
+"""
+from __future__ import annotations
+import concurrent.futures
+import hashlib
+import json
+import subprocess
+import zipfile
+from pathlib import Path
+import requests
+
+ROOT = Path(__file__).resolve().parent.parent
+KIT = ROOT / ".build/kit"
+CACHE = ROOT / ".build-cache/release-sources"
+FFMPEG_REVISION = "17ec99894249a68444d145ea8870713a4fb7f342"
+BUILD_REVISION = "8fc3fe09d1d84a10cecc2b08706e303e27e64834"
+
+
+def download(item):
+    CACHE.mkdir(parents=True, exist_ok=True)
+    target = CACHE / item["file"]
+    if not target.is_file():
+        response = requests.get(item["url"], timeout=(20, 180))
+        response.raise_for_status()
+        target.write_bytes(response.content)
+    data = target.read_bytes()
+    checksum = hashlib.sha256(data).hexdigest()
+    if item.get("expectedSHA256") and item["expectedSHA256"] != checksum:
+        raise ValueError(f"Source hash mismatch: {item['file']}")
+    print(f"Source: {item['file']} ({len(data)} bytes)", flush=True)
+    return {**item, "sha256": checksum, "bytes": len(data)}
+
+
+def main():
+    manifest = json.loads((ROOT / "dist/YouTubeDL-Helper-manifest.json").read_text(encoding="utf-8"))
+    sources = [
+        {"file": f"FFmpeg-{FFMPEG_REVISION}.tar.gz", "url": f"https://codeload.github.com/FFmpeg/FFmpeg/tar.gz/{FFMPEG_REVISION}", "component": "FFmpeg"},
+        {"file": f"FFmpeg-Builds-{BUILD_REVISION}.tar.gz", "url": f"https://codeload.github.com/yt-dlp/FFmpeg-Builds/tar.gz/{BUILD_REVISION}", "component": "FFmpeg build and dependency source recipes"},
+    ]
+    for metadata in sorted((KIT / "runtime/python/Lib/site-packages").glob("*.dist-info/METADATA")):
+        fields = dict(line.split(": ", 1) for line in metadata.read_text(encoding="utf-8").splitlines() if line.startswith(("Name: ", "Version: ")))
+        name, version = fields["Name"], fields["Version"]
+        response = requests.get(f"https://pypi.org/pypi/{name}/{version}/json", timeout=30)
+        response.raise_for_status()
+        sdist = next((file for file in response.json()["urls"] if file["packagetype"] == "sdist"), None)
+        if sdist:
+            sources.append({"file": sdist["filename"], "url": sdist["url"], "expectedSHA256": sdist["digests"]["sha256"], "component": f"{name} {version}"})
+    with concurrent.futures.ThreadPoolExecutor(max_workers=4) as pool:
+        records = list(pool.map(download, sources))
+    configuration = subprocess.run([str(KIT / "runtime/bin/ffmpeg.exe"), "-version"], capture_output=True, text=True, check=True).stdout
+    destination = ROOT / "dist/YouTubeDL-ThirdParty-Materials.zip"
+    with zipfile.ZipFile(destination,"w",zipfile.ZIP_DEFLATED) as archive:
+        for name in ("THIRD_PARTY.md", "LICENSE", "CONTRIBUTING.md"):
+            archive.write(ROOT / name, name)
+        archive.writestr("helper-manifest.json", json.dumps(manifest,indent=2))
+        archive.writestr("source-index.json", json.dumps(records,indent=2))
+        archive.writestr("FFmpeg-configuration.txt", configuration)
+        archive.writestr("SOURCE-README.txt", f"""YouTubeDL helper {manifest['version']}: upstream source materials and licenses.
+The exact FFmpeg source revision is in sources/; FFmpeg-Builds scripts contain
+the pinned download and build recipes for its third-party libraries.
+Extract the FFmpeg-Builds source archive and follow its Docker build instructions.
+Run ./download.sh win64 gpl-shared to fetch dependency sources; build.sh is the
+corresponding build recipe. Read scripts.d, variants and util for configuration.
+The supplied FFmpeg binary is unchanged from yt-dlp/FFmpeg-Builds.
+Python and Node.js official sources:
+https://www.python.org/ftp/python/3.13.14/Python-3.13.14.tgz
+https://nodejs.org/dist/v24.21.0/node-v24.21.0.tar.xz
+Python package source distributions are included where PyPI provides them.
+The original installer source and Native Messaging helper source are in the
+YouTubeDL repository. The root LICENSE governs original YouTubeDL materials.
+Third-party components are distributed under their own licenses; see THIRD_PARTY.md.
+""")
+        for record in records:
+            archive.write(CACHE / record["file"], "sources/" + record["file"])
+        for file in KIT.rglob("*"):
+            if not file.is_file(): continue
+            relative = file.relative_to(KIT)
+            if "licenses" in relative.parts or (".dist-info" in str(relative) and (file.name == "METADATA" or any(word in str(relative).lower() for word in ("license","copying","notice")))) or file.name == "LICENSE.txt":
+                archive.write(file,"licenses/" + str(relative).replace("\\","/"))
+    print(f"Materials: {destination.name} ({destination.stat().st_size} bytes)", flush=True)
+
+
+if __name__ == "__main__": main()

tools/run-installer-test.ps1

@@ -0,0 +1,16 @@
+param([Parameter(Mandatory=$true)][string]$InstallerPath)
+$ErrorActionPreference = 'Stop'
+$taskInstaller = (Resolve-Path -LiteralPath $InstallerPath).Path
+$taskPreviousFlag = $env:YTDL_INSTALL_NONINTERACTIVE
+try {
+    if ($taskInstaller.EndsWith('.exe', [StringComparison]::OrdinalIgnoreCase)) {
+        $taskProcess = Start-Process -FilePath $taskInstaller -ArgumentList '--silent' -WindowStyle Hidden -Wait -PassThru
+        if ($taskProcess.ExitCode -ne 0) { throw "Offline installer failed: $($taskProcess.ExitCode)" }
+        return
+    }
+    $env:YTDL_INSTALL_NONINTERACTIVE = '1'
+    & $taskInstaller
+    if ($LASTEXITCODE -ne 0) { throw "Helper installer failed: $LASTEXITCODE" }
+} finally {
+    $env:YTDL_INSTALL_NONINTERACTIVE = $taskPreviousFlag
+}

tools/setup.cs

@@ -0,0 +1,412 @@
+// Offline installer and ownership-scoped uninstaller. .NET Framework is part of Windows.
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Drawing;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using System.Security.Cryptography;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Web.Script.Serialization;
+using System.Windows.Forms;
+using Microsoft.Win32;
+
+internal static class Program
+{
+    const string Version = "@BUNDLE_VERSION@";
+    const string BundleHash = "@BUNDLE_HASH@";
+    const string Product = "YouTubeDL.Helper";
+    const string Host = "com.youtubedl.native";
+    const string UninstallKey = @"Software\Microsoft\Windows\CurrentVersion\Uninstall\YouTubeDL.Helper";
+    static readonly string[] Browsers = { @"Google\Chrome", @"Microsoft\Edge", "Chromium" };
+    static readonly JavaScriptSerializer Json = new JavaScriptSerializer { MaxJsonLength = 16 * 1024 * 1024 };
+
+    [STAThread]
+    public static int Main(string[] args)
+    {
+        Console.SetOut(new StreamWriter(Console.OpenStandardOutput(), new UTF8Encoding(false)) { AutoFlush = true });
+        Console.SetError(new StreamWriter(Console.OpenStandardError(), new UTF8Encoding(false)) { AutoFlush = true });
+        AppContext.SetSwitch("Switch.System.IO.UseLegacyPathHandling", false);
+        AppContext.SetSwitch("Switch.System.IO.BlockLongPaths", false);
+        if (args.Contains("--pick-folder"))
+        {
+            Application.EnableVisualStyles();
+            using (var dialog = new FolderBrowserDialog())
+            using (var owner = new Form { TopMost = true, ShowInTaskbar = false, Opacity = 0 })
+            {
+                string initial = Value(args, "--initial-folder");
+                if (initial != null) dialog.SelectedPath = Json.Deserialize<string>(Encoding.UTF8.GetString(Convert.FromBase64String(initial)));
+                dialog.Description = "YouTubeDL — папка сохранения"; dialog.ShowNewFolderButton = true;
+                owner.Show();
+                Console.WriteLine(Json.Serialize(dialog.ShowDialog(owner) == DialogResult.OK ? dialog.SelectedPath : null));
+                return 0;
+            }
+        }
+        bool silent = args.Contains("--silent");
+        bool uninstall = args.Contains("--uninstall");
+        string explicitRoot = Value(args, "--target-root");
+        string appRoot = Path.GetFullPath(explicitRoot ?? (uninstall ? Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)
+            : Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "YouTubeDL", "Helper"))).TrimEnd(Path.DirectorySeparatorChar);
+        Action<Action<int, string>> work = report => Run(appRoot, args, uninstall, report);
+        if (silent)
+        {
+            string previous = null;
+            try { work((percent, message) => { if (message != previous) Console.WriteLine(message); previous = message; }); return 0; }
+            catch (Exception error) { Console.Error.WriteLine(error.ToString()); return 1; }
+        }
+        Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false);
+        var window = new SetupWindow(work, uninstall);
+        Application.Run(window);
+        return window.ExitCode;
+    }
+
+    static string Value(string[] args, string key)
+    {
+        int index = Array.IndexOf(args, key);
+        return index >= 0 && index + 1 < args.Length ? args[index + 1] : null;
+    }
+
+    static void Run(string root, string[] args, bool uninstall, Action<int, string> report)
+    {
+        if (Path.GetPathRoot(root).TrimEnd('\\') == root.TrimEnd('\\') || root == Environment.GetFolderPath(Environment.SpecialFolder.UserProfile))
+            throw new Exception("Некорректная папка установки.");
+        if (Directory.Exists(root) && (File.GetAttributes(root) & FileAttributes.ReparsePoint) != 0)
+            throw new Exception("Папка установки не должна быть символической ссылкой.");
+        string waiting = Value(args, "--wait-pid");
+        if (waiting != null)
+        {
+            try { using (var parent = Process.GetProcessById(Int32.Parse(waiting))) { if (!parent.WaitForExit(30000)) throw new Exception("Помощник ещё работает. Закройте меню и повторите удаление."); } }
+            catch (ArgumentException) { }
+        }
+        if (!uninstall && !args.Contains("--finish-uninstall"))
+        {
+            Directory.CreateDirectory(root);
+            if (!args.Contains("--activate-release"))
+            {
+                // AppData virtualization can merge an existing real directory
+                // with newly created children elsewhere. Resolve a fresh child
+                // to find the directory where this install will actually write.
+                string probeName = ".ytdl-location-" + Guid.NewGuid().ToString("N");
+                string probe = Inside(root, probeName);
+                Directory.CreateDirectory(probe);
+                string physicalProbe = PhysicalDirectory(probe);
+                if (!String.Equals(Path.GetFileName(physicalProbe), probeName, StringComparison.OrdinalIgnoreCase))
+                    throw new Exception("Не удалось определить папку установки.");
+                root = Path.GetDirectoryName(physicalProbe);
+                Directory.Delete(physicalProbe, false);
+            }
+        }
+        // Keep the manager, marker and runtime in the same physical directory.
+        root = PhysicalDirectory(root).TrimEnd(Path.DirectorySeparatorChar);
+        string key;
+        using (var sha = SHA256.Create()) key = BitConverter.ToString(sha.ComputeHash(Encoding.UTF8.GetBytes(PhysicalDirectory(root).ToLowerInvariant()))).Replace("-", "").Substring(0, 16);
+        using (var mutex = new Mutex(false, "Local\\YouTubeDL.Setup." + key))
+        {
+            if (!mutex.WaitOne(0)) throw new Exception("Другая установка или удаление уже выполняется.");
+            try
+            {
+                if (args.Contains("--activate-release")) Activate(root, args, report);
+                else if (args.Contains("--finish-uninstall")) FinishRemoval(root, report);
+                else if (uninstall) Uninstall(root, report);
+                else
+                {
+#if SETUP
+                    Install(root, !args.Contains("--no-register"), report);
+#else
+                    throw new Exception("Для установки запустите YouTubeDL-Helper-Setup.exe.");
+#endif
+                }
+            }
+            finally { mutex.ReleaseMutex(); }
+        }
+    }
+
+    static string Inside(string root, string relative)
+    {
+        if (String.IsNullOrWhiteSpace(relative) || Path.IsPathRooted(relative)) throw new Exception("Некорректный путь в комплекте.");
+        string full = Path.GetFullPath(Path.Combine(root, relative));
+        if (!full.StartsWith(root.TrimEnd('\\') + "\\", StringComparison.OrdinalIgnoreCase)) throw new Exception("Путь выходит за папку комплекта.");
+        for (var parent = new DirectoryInfo(Path.GetDirectoryName(full)); parent != null && parent.FullName.Length >= root.Length; parent = parent.Parent)
+            if (parent.Exists && (parent.Attributes & FileAttributes.ReparsePoint) != 0) throw new Exception("Символические ссылки в папке комплекта не поддерживаются.");
+        if (File.Exists(full) && (File.GetAttributes(full) & FileAttributes.ReparsePoint) != 0) throw new Exception("Файл комплекта заменён символической ссылкой.");
+        return full;
+    }
+
+    static string Hash(Stream stream)
+    { using (var sha = SHA256.Create()) return BitConverter.ToString(sha.ComputeHash(stream)).Replace("-", "").ToLowerInvariant(); }
+
+    static Dictionary<string, object> ObjectFile(string path)
+    { return Json.Deserialize<Dictionary<string, object>>(File.ReadAllText(path, Encoding.UTF8)); }
+
+#if SETUP
+    static void Install(string root, bool register, Action<int, string> report)
+    {
+        report(2, "Проверяю автономный комплект…");
+        string releases = Path.Combine(root, "releases"); Directory.CreateDirectory(releases);
+        string stage = Inside(releases, Version + "-" + Guid.NewGuid().ToString("N").Substring(0, 8)); Directory.CreateDirectory(stage);
+        string archive = Inside(stage, "payload.zip");
+        string release = null;
+        bool installed = false;
+        try
+        {
+            using (var input = Assembly.GetExecutingAssembly().GetManifestResourceStream("bundle.zip"))
+            using (var output = File.Create(archive)) input.CopyTo(output);
+            using (var input = File.OpenRead(archive)) if (Hash(input) != BundleHash) throw new Exception("Контрольная сумма комплекта не совпала.");
+            using (var zip = ZipFile.OpenRead(archive))
+            {
+                long total = zip.Entries.Sum(entry => entry.Length), written = 0;
+                if (total > 1024L * 1024 * 1024) throw new Exception("Некорректный размер комплекта.");
+                foreach (var entry in zip.Entries)
+                {
+                    if (entry.FullName.EndsWith("/")) continue;
+                    if (((entry.ExternalAttributes >> 16) & 0xF000) == 0xA000) throw new Exception("Символическая ссылка в архиве.");
+                    string destination = Inside(stage, entry.FullName);
+                    Directory.CreateDirectory(Path.GetDirectoryName(destination));
+                    using (var input = entry.Open()) using (var output = File.Create(destination)) input.CopyTo(output);
+                    written += entry.Length;
+                    report(5 + (int)(written * 70 / total), "Распаковываю компоненты…");
+                }
+            }
+            File.Delete(archive);
+            report(78, "Проверяю Python, загрузчик, JavaScript и FFmpeg…");
+            // Virus scanners can briefly hold a newly extracted EXE or DLL.
+            for (int attempt = 0; ; attempt++)
+            {
+                try { Python(stage, "verify"); break; }
+                catch { if (attempt == 2) throw; Thread.Sleep(700 * (attempt + 1)); }
+            }
+            release = stage;
+            Python(release, "configure");
+            string manager = Inside(root, "YouTubeDL-Manager.exe");
+            using (var input = Assembly.GetExecutingAssembly().GetManifestResourceStream("manager.exe"))
+            using (var output = File.Create(manager)) input.CopyTo(output);
+            string marker = Inside(root, "installation.json");
+            string history = Inside(root, @"data\completed-jobs.json");
+            string previousHistory = Inside(root, @".runtime\completed-jobs.json");
+            if (!File.Exists(history) && File.Exists(previousHistory))
+            { Directory.CreateDirectory(Path.GetDirectoryName(history)); File.Copy(previousHistory, history); }
+            File.WriteAllText(marker, Json.Serialize(new { product = Product, version = Version, current = release, registered = register }), Encoding.UTF8);
+            string updates = Inside(root, @"data\update-settings.json");
+            if (File.Exists(updates))
+            { var options = ObjectFile(updates); options["lastCheck"] = 0; File.WriteAllText(updates, Json.Serialize(options), new UTF8Encoding(false)); }
+            if (register)
+            {
+                report(92, "Подключаю помощник к Edge и Chrome…");
+                foreach (string browser in Browsers)
+                    using (var registry = Registry.CurrentUser.CreateSubKey(@"Software\" + browser + @"\NativeMessagingHosts\" + Host))
+                        registry.SetValue("", Path.Combine(release, @".runtime\native-host.json"));
+                using (var registry = Registry.CurrentUser.CreateSubKey(UninstallKey))
+                {
+                    registry.SetValue("DisplayName", "YouTubeDL Helper"); registry.SetValue("DisplayVersion", Version);
+                    registry.SetValue("Publisher", "YouTubeDL"); registry.SetValue("InstallLocation", root);
+                    registry.SetValue("UninstallString", "\"" + manager + "\" --uninstall");
+                    registry.SetValue("QuietUninstallString", "\"" + manager + "\" --uninstall --silent");
+                    registry.SetValue("NoModify", 1); registry.SetValue("NoRepair", 1);
+                }
+            }
+            installed = true;
+            report(100, "Готово. Вернитесь в YouTubeDL и нажмите «Запустить».");
+        }
+        finally
+        {
+            // Only this freshly generated, unpublished folder may be removed.
+            // Cleanup must not hide the original validation/installation error.
+            try
+            {
+                if (!installed && Directory.Exists(stage) && (File.GetAttributes(stage) & FileAttributes.ReparsePoint) == 0)
+                {
+                    var candidates = Directory.EnumerateFileSystemEntries(stage, "*", SearchOption.AllDirectories).ToArray();
+                    if (candidates.All(path => (File.GetAttributes(path) & FileAttributes.ReparsePoint) == 0)) Directory.Delete(stage, true);
+                }
+            }
+            catch (IOException) { } catch (UnauthorizedAccessException) { }
+        }
+    }
+
+#endif
+
+    static void Activate(string root, string[] args, Action<int, string> report)
+    {
+        string marker = Inside(root, "installation.json");
+        var previous = ObjectFile(marker);
+        if ((string)previous["product"] != Product) throw new Exception("Установленный комплект не найден.");
+        string expected = PhysicalDirectory(Value(args, "--expected-current"));
+        string current = PhysicalDirectory((string)previous["current"]);
+        if (!String.Equals(current, expected, StringComparison.OrdinalIgnoreCase)) throw new Exception("Помощник уже изменён другой установкой. Повторите проверку обновлений.");
+        string stage = PhysicalDirectory(Path.GetFullPath(Value(args, "--activate-release")));
+        if (!String.Equals(Path.GetDirectoryName(stage), PhysicalDirectory(Inside(root, "releases")), StringComparison.OrdinalIgnoreCase)) throw new Exception("Папка обновления вне комплекта.");
+        var metadata = ObjectFile(Inside(stage, "bundle.json"));
+        if ((string)metadata["product"] != Product || (string)metadata["mode"] != "autonomous") throw new Exception("Некорректный комплект обновления.");
+        report(10, "Проверяю контрольные суммы обновления…");
+        foreach (var entry in ObjectFile(Inside(stage, "bundle-files.json")))
+            using (var input = File.OpenRead(Inside(stage, entry.Key)))
+                if (Hash(input) != (string)entry.Value) throw new Exception("Повреждён компонент обновления: " + entry.Key);
+        for (int attempt = 0; ; attempt++)
+        { try { Python(stage, "verify"); break; } catch { if (attempt == 2) throw; Thread.Sleep(700 * (attempt + 1)); } }
+        Python(stage, "configure");
+        var registrations = new Dictionary<string, string>();
+        string nextMarker = Inside(root, "installation.next.json");
+        try
+        {
+            if ((bool)previous["registered"])
+                foreach (string browser in Browsers)
+                {
+                    string name = @"Software\" + browser + @"\NativeMessagingHosts\" + Host;
+                    using (var registry = Registry.CurrentUser.OpenSubKey(name, true))
+                    {
+                        string value = registry == null ? null : registry.GetValue("") as string;
+                        if (value == null || !String.Equals(PhysicalDirectory(Path.GetDirectoryName(value)), PhysicalDirectory(Path.Combine(current, ".runtime")), StringComparison.OrdinalIgnoreCase)) continue;
+                        registrations[name] = value; registry.SetValue("", Path.Combine(stage, @".runtime\native-host.json"));
+                    }
+                }
+            File.WriteAllText(nextMarker, Json.Serialize(new { product = Product, version = (string)metadata["version"], current = stage, registered = (bool)previous["registered"] }), Encoding.UTF8);
+            File.Replace(nextMarker, marker, null);
+        }
+        catch
+        {
+            foreach (var entry in registrations) using (var registry = Registry.CurrentUser.CreateSubKey(entry.Key)) registry.SetValue("", entry.Value);
+            if (File.Exists(nextMarker)) File.Delete(nextMarker);
+            throw;
+        }
+        report(100, "Новые компоненты подключены.");
+    }
+
+    static void Python(string root, string action)
+    {
+        var start = new ProcessStartInfo(Inside(root, @"runtime\python\python.exe"), "-I -X utf8 -B -m host.bootstrap " + action)
+        { UseShellExecute = false, CreateNoWindow = true, RedirectStandardOutput = true, RedirectStandardError = true,
+          StandardOutputEncoding = Encoding.UTF8, StandardErrorEncoding = Encoding.UTF8 };
+        start.EnvironmentVariables["PYTHONPATH"] = "C:\\NONEXISTENT"; start.EnvironmentVariables["PYTHONHOME"] = "C:\\NONEXISTENT";
+        start.EnvironmentVariables["PYTHONDONTWRITEBYTECODE"] = "1";
+        start.EnvironmentVariables["PATH"] = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Windows), "System32");
+        using (var process = Process.Start(start))
+        {
+            var stdout = process.StandardOutput.ReadToEndAsync(); var stderr = process.StandardError.ReadToEndAsync();
+            if (!process.WaitForExit(90000)) throw new Exception("Проверка комплекта заняла слишком много времени.");
+            if (process.ExitCode != 0) throw new Exception("Комплект не прошёл проверку: " + stderr.Result + stdout.Result);
+        }
+    }
+
+    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+    static extern Microsoft.Win32.SafeHandles.SafeFileHandle CreateFileW(string path, uint access, uint share, IntPtr security, uint disposition, uint flags, IntPtr template);
+    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+    static extern uint GetFinalPathNameByHandleW(Microsoft.Win32.SafeHandles.SafeFileHandle file, StringBuilder name, uint length, uint flags);
+    static string PhysicalDirectory(string path)
+    {
+        using (var handle = CreateFileW(path, 0, 7, IntPtr.Zero, 3, 0x02000000, IntPtr.Zero))
+        {
+            if (handle.IsInvalid) return Path.GetFullPath(path);
+            var name = new StringBuilder(32768);
+            if (GetFinalPathNameByHandleW(handle, name, (uint)name.Capacity, 0) == 0) return Path.GetFullPath(path);
+            string value = name.ToString();
+            return value.StartsWith(@"\\?\UNC\") ? @"\\" + value.Substring(8) : value.StartsWith(@"\\?\") ? value.Substring(4) : value;
+        }
+    }
+
+    static void Uninstall(string root, Action<int, string> report)
+    {
+        string marker = Inside(root, "installation.json");
+        if (!File.Exists(marker) || (string)ObjectFile(marker)["product"] != Product) throw new Exception("Установленный комплект YouTubeDL не найден.");
+        string physicalRoot = PhysicalDirectory(root);
+        report(5, "Отключаю помощник…");
+        foreach (string browser in Browsers)
+        {
+            string name = @"Software\" + browser + @"\NativeMessagingHosts\" + Host;
+            using (var registry = Registry.CurrentUser.OpenSubKey(name))
+            {
+                string value = registry == null ? null : registry.GetValue("") as string;
+                if (value == null || !PhysicalDirectory(Path.GetDirectoryName(value)).StartsWith(physicalRoot + "\\releases\\", StringComparison.OrdinalIgnoreCase)) continue;
+            }
+            Registry.CurrentUser.DeleteSubKey(name, false);
+        }
+        using (var registry = Registry.CurrentUser.OpenSubKey(UninstallKey))
+        { if (registry != null && registry.GetValue("InstallLocation") is string && String.Equals(PhysicalDirectory((string)registry.GetValue("InstallLocation")), physicalRoot, StringComparison.OrdinalIgnoreCase)) Registry.CurrentUser.DeleteSubKeyTree(UninstallKey, false); }
+        string releases = Inside(root, "releases");
+        string[] packages = Directory.Exists(releases) ? Directory.GetDirectories(releases) : new string[0];
+        int done = 0;
+        foreach (string release in packages)
+        {
+            Inside(root, release.Substring(root.Length + 1) + "\\bundle.json");
+            if (!File.Exists(Path.Combine(release, "bundle.json")) || !File.Exists(Path.Combine(release, "bundle-files.json")) || (string)ObjectFile(Path.Combine(release, "bundle.json"))["product"] != Product) continue;
+            var records = ObjectFile(Path.Combine(release, "bundle-files.json"));
+            var directories = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+            foreach (string relative in records.Keys.Concat(new[] { "bundle-files.json", ".runtime/native-host.json", ".runtime/launch-host.cmd" }))
+            {
+                string path = Inside(release, relative);
+                if (File.Exists(path)) File.Delete(path);
+                for (string parent = Path.GetDirectoryName(path); parent != null && parent.StartsWith(release, StringComparison.OrdinalIgnoreCase); parent = Path.GetDirectoryName(parent)) directories.Add(parent);
+            }
+            foreach (string directory in directories.OrderByDescending(path => path.Length)) TryRemoveEmpty(directory);
+            report(10 + (++done * 80 / Math.Max(1, packages.Length)), "Удаляю встроенные компоненты…");
+        }
+        TryRemoveEmpty(releases);
+        string manager = Inside(root, "YouTubeDL-Manager.exe");
+        // Run the final cleanup outside the installed directory, after this EXE exits.
+        // The same mutex and an installation-marker check prevent a reinstall race.
+        if (File.Exists(manager))
+        {
+            string pending = Inside(root, "uninstall-pending.json");
+            File.WriteAllText(pending, Json.Serialize(new { product = Product }), Encoding.UTF8);
+            string cleanup = Path.Combine(Path.GetTempPath(), "YouTubeDL-Cleanup-" + Guid.NewGuid().ToString("N") + ".exe");
+            // Do not carry EFS attributes from AppData into the browser's temp
+            // directory; that directory may reside on a different volume.
+            File.WriteAllBytes(cleanup, File.ReadAllBytes(manager));
+            Process.Start(new ProcessStartInfo(cleanup, "--finish-uninstall --silent --target-root \"" + root + "\" --wait-pid " + Process.GetCurrentProcess().Id)
+                { UseShellExecute = false, CreateNoWindow = true });
+        }
+        File.Delete(marker);
+        report(100, "Помощник удалён. Скачанные ролики сохранены.");
+    }
+
+    static void FinishRemoval(string root, Action<int, string> report)
+    {
+        string pending = Inside(root, "uninstall-pending.json");
+        if (!File.Exists(pending) || (string)ObjectFile(pending)["product"] != Product) return;
+        if (!File.Exists(Inside(root, "installation.json"))) File.Delete(Inside(root, "YouTubeDL-Manager.exe"));
+        File.Delete(pending); TryRemoveEmpty(root);
+    }
+
+    static void TryRemoveEmpty(string path)
+    { try { if (Directory.Exists(path) && (File.GetAttributes(path) & FileAttributes.ReparsePoint) == 0) Directory.Delete(path, false); } catch (IOException) { } }
+}
+
+internal sealed class SetupWindow : Form
+{
+    readonly Action<Action<int, string>> work;
+    readonly Label message;
+    readonly ProgressBar progress;
+    readonly Button close;
+    bool working = true;
+    public int ExitCode = 0;
+    public SetupWindow(Action<Action<int, string>> task, bool uninstall)
+    {
+        work = task; Text = "YouTubeDL"; Size = new Size(560, 285); StartPosition = FormStartPosition.CenterScreen;
+        FormBorderStyle = FormBorderStyle.FixedDialog; MaximizeBox = false; Font = new Font("Segoe UI", 10);
+        bool light = true;
+        using (var theme = Registry.CurrentUser.OpenSubKey(@"Software\Microsoft\Windows\CurrentVersion\Themes\Personalize"))
+            light = theme == null || Convert.ToInt32(theme.GetValue("AppsUseLightTheme", 1)) != 0;
+        BackColor = light ? Color.FromArgb(248, 249, 251) : Color.FromArgb(22, 25, 31);
+        ForeColor = light ? Color.FromArgb(25, 30, 40) : Color.FromArgb(235, 241, 248);
+        var title = new Label { Text = uninstall ? "Удаление помощника" : "Установка помощника", Location = new Point(28, 24), AutoSize = true, Font = new Font("Segoe UI", 17, FontStyle.Bold) };
+        var subtitle = new Label { Text = "YouTubeDL · автономный комплект " + "@BUNDLE_VERSION@", Location = new Point(30, 65), AutoSize = true };
+        message = new Label { Text = "Подготавливаю…", Location = new Point(30, 105), Size = new Size(475, 47) };
+        progress = new ProgressBar { Location = new Point(30, 154), Size = new Size(480, 8), Style = ProgressBarStyle.Continuous };
+        close = new Button { Text = "Закрыть", Location = new Point(394, 189), Size = new Size(115, 33), Enabled = false, FlatStyle = FlatStyle.Flat };
+        close.Click += (sender, args) => Close(); Controls.AddRange(new Control[] { title, subtitle, message, progress, close });
+        FormClosing += (sender, args) => { if (working) args.Cancel = true; };
+        Shown += async (sender, args) =>
+        {
+            try
+            {
+                await Task.Run(() => work((percent, text) => BeginInvoke(new Action(() => { progress.Value = Math.Max(0, Math.Min(100, percent)); message.Text = text; }))));
+            }
+            catch (Exception error) { ExitCode = 1; message.Text = error.Message; }
+            finally { working = false; close.Enabled = true; close.Focus(); }
+        };
+    }
+}

tools/setup.manifest

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="1.0.0.0" name="YouTubeDL.Setup"/>
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3"><security><requestedPrivileges><requestedExecutionLevel level="asInvoker" uiAccess="false"/></requestedPrivileges></security></trustInfo>
+  <application xmlns="urn:schemas-microsoft-com:asm.v3"><windowsSettings><longPathAware xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">true</longPathAware><dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true</dpiAware></windowsSettings></application>
+  <dependency><dependentAssembly><assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" processorArchitecture="*" publicKeyToken="6595b64144ccf1df" language="*"/></dependentAssembly></dependency>
+</assembly>

uninstall.ps1

@@ -0,0 +1,13 @@
+[CmdletBinding()]
+param()
+$ErrorActionPreference = 'Stop'
+$taskExpectedManifest = Join-Path $PSScriptRoot '.runtime\native-host.json'
+foreach ($taskBrowser in @('Google\Chrome','Microsoft\Edge','Chromium')) {
+    $taskRegistryPath = "HKCU:\Software\$taskBrowser\NativeMessagingHosts\com.youtubedl.native"
+    if (Test-Path -LiteralPath $taskRegistryPath) {
+        $taskCurrentManifest = (Get-Item -LiteralPath $taskRegistryPath).GetValue('')
+        if ($taskCurrentManifest -eq $taskExpectedManifest) { Remove-Item -LiteralPath $taskRegistryPath }
+    }
+}
+Write-Host 'Native helper unregistered. Remove YouTubeDL from the browser extensions page.'
+Write-Host 'Downloaded media files have not been removed.'