- _cookie_args() no longer falls through to --cookies-from-browser when
cookies_file is configured but missing. Firefox isn't installed in the
Docker image, so that fallback caused yt-dlp to exit with empty stdout
and every metadata fetch to return "Video not found on YouTube".
- fetch_video_metadata() now retries without auth args if the first call
fails, so a broken cookie config can't block public video fetches.
- Add use_oauth2 setting + full device-auth flow (POST /settings/oauth2-init,
GET /settings/oauth2-status) with OAuth2Section UI in Settings page.
- Add GET /settings/ytdlp-test diagnostics endpoint.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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