Phase 2: Controlled Writes

• Add broker endpoints for explicit RG actions only after the data source is clear:
  • toggle watchlist/favorite
  • set rating
  • maybe mark watched
• Broker writes to Jellyfin/StarTrack/LetterboxdSync, not directly from RG to Letterboxd.
• Keep Letterboxd credentials off the RG.

Open Questions

• Which plugin should be canonical for writes: StarTrack, LetterboxdSync, or Jellyfin UserData?
• Should RG allow writing ratings at all, or only display what Jellyfin already knows?
• Are review bodies useful on a 640x480 screen, or should RG show only rating, watched, liked, and watchlist state?