Extracts the repeated toolbar fade into a single ToolbarScrim widget, folds
duplicated request/retry handling in the media server HTTP client, and
collapses the parallel playback-source, download-manager and live TV helper
paths into shared implementations.
Un-gates music libraries; adds CardShape.square plumbing (circular
artists), artists/albums/tracks browse groupings with per-grouping
sorts, audio playlists tab, artist + album detail screens with dpad
track rows, music context-menu actions, and a stub MusicPlaybackService
seam for the upcoming engine.
- Replace hardcoded 4-tab system with data-driven visible tab list
- Shared libraries show only Browse + Playlists tabs
- Fix dpad navigation for shared libraries (no hidden tab targets)
- Switch to TickerProviderStateMixin to support tab controller recreation
- Navigate to library screen when tapping shared library sections
- Persist tab selection by name instead of index
Extract EpisodeCard to its own widget file. MediaDetailScreen now handles
isSeason by showing episodes directly, with proper watch state tracking,
deletion handling, and D-pad focus navigation. Hide empty overview sections.