fix(player): keep an explicit track choice through the pending automatic pass

When a source advertises subtitles the native track list has not
produced yet, applyTrackSelectionWhenReady keeps an automatic selection
armed for up to thirty seconds. That late pass re-runs
TrackSelectionService against the stored preferences, so a track the
user picked in the meantime was silently reset. The Maestro codec suites
caught it: the English E-AC3 and Japanese DTS-HD flows select an audio
track, and fifteen seconds later the deadline puts the preferred
language back.

Adds explicit user-selection entry points that retire the pending
automatic selection first, and routes the sheet callbacks and the
remote's cycle shortcuts through them. Subtitles get the same treatment,
because the same pass re-selects them.

Bumping the generation is sufficient: TrackSelectionService re-checks it
in the statement immediately before each select call, and a mutation
already in flight was dispatched before the user's and so lands first.

lib/screens/video_player_screen.dart

@@ -1763,11 +1763,11 @@ class VideoPlayerScreenState extends State<VideoPlayerScreen> with WidgetsBindin
     }
   }
 
-  Future<void> _onAudioTrackChanged(AudioTrack track) async => _trackManager?.onAudioTrackChanged(track);
+  Future<void> _onAudioTrackChanged(AudioTrack track) async => _trackManager?.onAudioTrackSelectedByUser(track);
 
   Future<void> _onSubtitleTrackChanged(SubtitleTrack track, {int? sourceStreamId}) async {
     _rememberNativeSubtitleSelection(track, sourceStreamId: sourceStreamId);
-    await _trackManager?.onSubtitleTrackChanged(track, sourceStreamId: sourceStreamId);
+    await _trackManager?.onSubtitleTrackSelectedByUser(track, sourceStreamId: sourceStreamId);
   }
 
   void _rememberNativeSubtitleSelection(SubtitleTrack track, {int? sourceStreamId}) {