v1.2.0

Changes

• Replace HTML5 Audio with ExoPlayer — native audio in foreground service for Android Auto & background playback
• WebView-JS bridge: playStream, nativeTogglePlay, nativeSeekTo, nativeSetVolume
• player.js: _native mode guards, delegates playback to AndroidBridge, persists state to SharedPreferences
• AudioService: ExoPlayer handles onPlayFromMediaId directly; manual audio focus removed (ExoPlayer internal)
• NavidromeClient: added getSong() for metadata resolution
• ExoPlayerHolder: singleton, position push every 250ms, onTrackEnded/onTrackError callbacks
• Update metadata through companion fn; stale-bitmap guard preserved
• Fix duration display: guard ExoPlayer TIME_UNSET before pushing to JS (was showing -153722867280913:-56)