Implement media downloading with foreground notification showing progress
percentage and speed. Uses Media3's DownloadManager + SimpleCache with
OkHttp datasource for authenticated Jellyfin downloads. Downloaded movies
are saved to the offline database and the player reads from cache
automatically via CacheDataSource.
- Add Media3 UI, ExoPlayer, and Compose dependencies.
- Implement `PlayerActivity` with landscape orientation for video playback.
- Create `PlayerViewModel` to manage ExoPlayer lifecycle and media loading via Hilt.
- Define `VideoPlayerModule` to provide a configured `ExoPlayer` instance with tunneling and custom load control.
- Extend `JellyfinApiClient` to fetch media sources and video stream URLs.
- Update `ContinueWatchingCard` to launch `PlayerActivity` when the play button is clicked.
- Enforce portrait orientation for the main application and filter duplicate items in `HomePageViewModel`.
- Setup Hilt for dependency injection and KSP for annotation processing.
- Add DataStore for user session management with JSON serialization.
- Integrate Jellyfin SDK and create a basic `JellyfinApiClient`.
- Replace `MainActivity` with `PurefinActivity` featuring a login flow and a placeholder home screen.
- Implement custom UI components: `PurefinComplexTextField`, `PurefinPasswordField`, and `PurefinTextButton`.
- Update version catalog with new dependencies and downgrade SDK versions to 35.
