FB Video Download por TSL

Adds download options right where you watch:

• Video player "…" menu: download options at the top of the menu
• Posts: a download button next to Share, showing the file size
• Reels: a download button above Like
• Stories: a download icon next to the sound / play controls (video stories only)

Options per video:
- Best quality: the highest-resolution stream with its audio, merged into one standard MP4 in your browser
- H.264: the same resolution re-encoded to H.264 (for apps such as Messenger that don't accept AV1/VP9)
- Facebook's ready-made files with audio (e.g. 720p, SD)

Files are named after the uploader and the post text. Everything runs locally in your browser; nothing is sent anywhere except the requests to Facebook's own servers for the video.