[ajisth69]

Summary

Fixes java.lang.IllegalStateException: Player is accessed on the wrong thread crash reported on Android 16 (CPH2793).

Root Cause

• \AutoDJController.attachHost\ collected settings in \�pplicationScope\ without specifying a dispatcher, running on \Dispatchers.Default\ (\DefaultDispatcher-worker-X).
• When calling \host.getQueueSize()\ and \host.getCurrentIndex(), the host callback in \MusicPlayer\ directly accessed \player.mediaItemCount\ and \player.currentMediaItemIndex\ on background worker threads, triggering ExoPlayer's application thread check.
• Secondary warm-prefetch in \AutoDJController\ also invoked \host.getQueueSize()\ and \host.getTrackAt()\ from \Dispatchers.IO.

Fix

1. Guard \AutoDJPlaybackHost\ queries in \MusicPlayer: if on the main looper, query \player; otherwise safely query _state.value.queue\ and _state.value.currentIndex\ without touching ExoPlayer.
2. Synchronize \playHistory\ operations to protect concurrent reads from \getRecentPlayedTrackIds().
3. Guard \currentPositionMs()\ to only query \player.currentPosition\ when on the main looper.
4. Launch \settingsPreferences.settings\ collection in \AutoDJController.attachHost\ on \Dispatchers.Main.immediate.