- Add `SyncCancelled` error variant for non-fatal cancellations
- Refactor queue sync to async via `MusicQueue::schedule_sync()`
- Extract browse+conversion into internal helper
- Update all `QueueBackend::sync_queue()` signatures to accept cancel token and on_ready callback
- Implement early-start logic (on pivot preservation or first insert)
- Add `QueueReadyToPlay` and ‘ QueueSyncCancelled➔ SSE events
- Replace blocking `refresh_attached_queue_for()` with non-blocking async dispatch in control_point.rs
- Bump version to v0.3.41
