Expose subtitle information in the API and update the frontend to use it: backend adds subtitle_languages and has_subtitles to the downloader serializer/response (computed from subtitles and automatic_captions). Generated TypeScript models (public & private) now include these fields. Downloader UI: gather available subtitle languages, show a select when languages exist, provide contextual input/placeholder when only auto-captions exist, and disable/annotate embed controls when subtitles or thumbnails are unavailable. These changes enable subtitle selection/embedding and surface thumbnail availability to users.
Brunobrno
e1df55df0e