chore: add sync indicator and better album state management (#20004)

* album list rerendering

* sync indicator

* sync indicator

* fix: lint

mobile/lib/providers/sync_status.provider.dart

@@ -0,0 +1,68 @@
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+
+enum SyncStatus {
+  idle,
+  syncing,
+  success,
+  error,
+}
+
+class SyncStatusState {
+  final SyncStatus remoteSyncStatus;
+  final String? errorMessage;
+
+  const SyncStatusState({
+    this.remoteSyncStatus = SyncStatus.idle,
+    this.errorMessage,
+  });
+
+  SyncStatusState copyWith({
+    SyncStatus? remoteSyncStatus,
+    String? errorMessage,
+  }) {
+    return SyncStatusState(
+      remoteSyncStatus: remoteSyncStatus ?? this.remoteSyncStatus,
+      errorMessage: errorMessage ?? this.errorMessage,
+    );
+  }
+
+  bool get isRemoteSyncing => remoteSyncStatus == SyncStatus.syncing;
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+    return other is SyncStatusState &&
+        other.remoteSyncStatus == remoteSyncStatus &&
+        other.errorMessage == errorMessage;
+  }
+
+  @override
+  int get hashCode => Object.hash(remoteSyncStatus, errorMessage);
+}
+
+class SyncStatusNotifier extends Notifier<SyncStatusState> {
+  @override
+  SyncStatusState build() {
+    return const SyncStatusState(
+      errorMessage: null,
+      remoteSyncStatus: SyncStatus.idle,
+    );
+  }
+
+  void setRemoteSyncStatus(SyncStatus status, [String? errorMessage]) {
+    state = state.copyWith(
+      remoteSyncStatus: status,
+      errorMessage: status == SyncStatus.error ? errorMessage : null,
+    );
+  }
+
+  void startRemoteSync() => setRemoteSyncStatus(SyncStatus.syncing);
+  void completeRemoteSync() => setRemoteSyncStatus(SyncStatus.success);
+  void errorRemoteSync(String error) =>
+      setRemoteSyncStatus(SyncStatus.error, error);
+}
+
+final syncStatusProvider =
+    NotifierProvider<SyncStatusNotifier, SyncStatusState>(
+  SyncStatusNotifier.new,
+);