Adds support for viewing and playing trailers and bonus content from Plex.
- Add getExtras() API method to fetch extras from Plex
- Add trailer/extras metadata fields (subtype, extraType, primaryExtraKey)
- Add play trailer button with film reel icon on media detail screen
- Add "Trailers & Extras" section below cast with horizontal scroll
- Support offline mode via cache fallback
- Preserve serverId/serverName for multi-server setups
Fixes#7
- Changed rating field type from int to double in PlexMetadata model
- Removed incorrect division by 10 in discover screen rating display
- Regenerated JSON serialization to properly parse rating as double
- Rating now displays correctly (e.g., 7.0 instead of 0.7)
Matt Vogel