Show folder names immediately and refresh stale index sizes without walking the whole drive.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/Explorer.Domain/Abstractions/IIndexStore.cs

@@ -159,6 +159,7 @@ public sealed class SourceSnapshot
 public interface IHashStore
 {
     Task EnqueueSizeCollisionsAsync(long? sourceId, CancellationToken cancellationToken = default);
+    Task<bool> HasPendingAsync(CancellationToken cancellationToken = default);
     Task<IReadOnlyList<HashWorkItem>> DequeueAsync(int take, CancellationToken cancellationToken = default);
     Task CompletePartialAsync(long entryId, byte[] hash, CancellationToken cancellationToken = default);
     Task CompleteFullAsync(long entryId, byte[] hash, CancellationToken cancellationToken = default);