- **Memory & Resource Management**:
    - Implement bounded caches for `AiPlaylistGenerator`, and `LyricsRepositoryImpl` using `LinkedHashMap` to prevent unbounded growth and potential memory leaks.
    - Explicitly nullify callbacks and providers in `AiStateHolder`'s `onCleared` method to break reference cycles.
    - Add a comprehensive `onCleared` method to `CastTransferStateHolder` to cancel jobs, unregister listeners, and nullify callbacks, preventing memory leaks.
    - Resolve a duplicate call to `listeningStatsTracker.onCleared()` and add a missing `castTransferStateHolder.onCleared()` in `PlayerViewModel`.
    - Ensure `DualPlayerEngine` removes its listener and abandons audio focus upon release.
    - Manage the `refreshRoutesJob` in `CastStateHolder` by canceling any existing job before starting a new one and on clear.

- **Performance & Bug Fixes**:
    - **Music Repository**: Optimize `getSongsByIds` by directly querying the DAO with a list of IDs instead of loading all songs into memory for filtering. This significantly improves performance for large libraries.
    - **Artist Image Prefetch**: Simplify the artist image prefetch logic by removing an unnecessary, manually-created coroutine scope.
    - **Widget Updates**: Refactor `WidgetUpdateReceiver` to use `goAsync()` and a dedicated coroutine scope, ensuring long-running update operations don't get terminated by the system.
    - **Sleep Timer**: Remove a redundant `delay`-based coroutine meant to clear UI state, as this is now handled more reliably by the `AlarmManager` broadcast.

- **Code Cleanup**:
    - Simplify log messages in `LogUtils.kt` by removing method and line number details, making them cleaner.