Media playback now survives navigation. A GlobalMediaPlayer singleton owns
VLC players and exposes StateFlows. Composables are thin viewports.
NowPlayingBar has full controls (volume, mute, save, fullscreen).
GlobalFullscreenOverlay renders video fullscreen above all screens.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
nrobi144