Integrate `navigation3` into `AppScreen` to manage tab transitions and
backstack state. Replaced manual tab state management with `NavDisplay`
and `NavBackStack`, and added horizontal slide animations for switching
between Home, Libraries, and Downloads screens.
Consolidates specific media selection callbacks (`onMovieSelected`, `onSeriesSelected`, `onEpisodeSelected`) into a single `onMediaSelected` handler that accepts a `MediaUiModel`. This simplifies the interface between the ViewModel and UI components across both mobile and TV screens, moving the type-checking logic into `AppViewModel`.
Adds the ability to play and pause media using the Center or Enter keys
without displaying the full player controls. When pausing via this
method, a brief visual "Pause" feedback overlay is shown in the center
of the screen.
- Added `TvPlayerHiddenStopFeedback` component and related logic
- Updated `handleTvPlayerRootKeyEvent` to support background playback toggling
- Added `pausePlayback` and `resumePlayback` to `PlayerViewModel` and `PlayerManager`
- Included comprehensive UI tests for the new hidden control behavior
Move the TV player queue into a simplified bottom inline playlist row and keep the existing seek bar -> controls -> playlist navigation hierarchy.
Focus playlist entry on the current queue item, keep focus pinned on the row at the horizontal edges, and return to the controls row on Up/Back.
Add compose coverage for playlist expansion, current-item focus, fallback focus, and row edge navigation.
Update directional key behavior to separate seeking, showing controls, and
toggling playback. Left/Right now seek without showing controls, while
Up/Down now only show controls instead of toggling playback.
