CloudKitRecordMapper was a standalone actor, so 'await recordMapper.toCKRecord'
from the @MainActor sync engine hopped off the main actor and read live
SwiftData @Model properties (e.g. LocalPlaylistItem.authorName) from the wrong
executor. SwiftData models are bound to the main ModelContext and are not
thread-safe, so this raced the backing store and crashed with EXC_BAD_ACCESS.
Make the mapper @MainActor (it must touch main-isolated models regardless) and
drop the now-redundant awaits. Fixes the crash for all synced model types.
Fixes an EXC_BAD_ACCESS seen in TestFlight build 261.
Pending deletes were lost across app restarts because
recoverPersistedPendingChanges() never reconstructed CKRecord.ID
objects from persisted record names. Additionally, incoming iCloud
records for deleted playlists were blindly applied, and orphaned
playlist items in CloudKit would recreate placeholder playlists.
- Rebuild pendingDeletes array from UserDefaults on recovery
- Guard applyRemoteRecord against records pending local deletion
- Skip deferred items whose parent playlist is pending deletion
- Queue all playlist item deletions when deleting a playlist
- Clean up placeholder playlists for pending-delete playlists
