- Replace object lock with SemaphoreSlim(1,1) on both DirectoryIndexDirectory
and VaultIndexDirectory; SaveIndexAsync now executes inside the semaphore
so mutate+persist is atomic
- ReloadIndexAsync acquires the semaphore before LoadIndexAsync so disk load
and in-memory swap are atomic with respect to concurrent writes
- HasIndexEntry and GetEntryMetadata converted to async Task with WaitAsync;
MediaVault.GetEntryAsync call sites updated accordingly
- TrackRepository.Update throws InvalidOperationException when Id not found
instead of silently calling Create; service layer catches and wraps as fail result
Daniel Harvey