fix(mobile): play videos from search results and folder view

mobile/lib/domain/models/asset/base_asset.model.dart

@@ -79,6 +79,17 @@ sealed class BaseAsset {
   bool get isLocalOnly => storage == AssetState.local;
   bool get isRemoteOnly => storage == AssetState.remote;
 
+  // Same asset even if localId is known on one side but not the other (heroTag isn't stable then)
+  bool isSameAsset(BaseAsset other) {
+    if (remoteId != null && other.remoteId != null) {
+      return remoteId == other.remoteId;
+    }
+    if (localId != null && other.localId != null) {
+      return localId == other.localId;
+    }
+    return checksum != null && checksum == other.checksum;
+  }
+
   bool get isEditable => false;
 
   // Overridden in subclasses

mobile/lib/presentation/widgets/asset_viewer/asset_page.widget.dart

@@ -395,7 +395,7 @@ class _AssetPageState extends ConsumerState<AssetPage> {
 
   @override
   Widget build(BuildContext context) {
-    final currentHeroTag = ref.watch(assetViewerProvider.select((s) => s.currentAsset?.heroTag));
+    final currentAsset = ref.watch(assetViewerProvider.select((s) => s.currentAsset));
     _showingDetails = ref.watch(assetViewerProvider.select((s) => s.showingDetails));
     final stackIndex = ref.watch(assetViewerProvider.select((s) => s.stackIndex));
     final isPlayingMotionVideo = ref.watch(isPlayingMotionVideoProvider);
@@ -414,7 +414,7 @@ class _AssetPageState extends ConsumerState<AssetPage> {
       displayAsset = stackChildren.elementAt(stackIndex);
     }
 
-    final isCurrent = currentHeroTag == displayAsset.heroTag;
+    final isCurrent = currentAsset != null && currentAsset.isSameAsset(displayAsset);
 
     final viewportWidth = MediaQuery.widthOf(context);
     final viewportHeight = MediaQuery.heightOf(context);

mobile/test/domain/models/base_asset_test.dart

@@ -0,0 +1,46 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../unit/factories/local_asset_factory.dart';
+import '../../unit/factories/remote_asset_factory.dart';
+
+void main() {
+  group('BaseAsset.isSameAsset', () {
+    test('search/folder copy (localId null) matches the merged DB copy (localId set)', () {
+      // #29472: search and folder assets arrive with localId null, then the viewer
+      // watches the DB copy which fills localId. heroTag embeds localId, so it
+      // diverges for the same asset and isCurrent used to go false.
+      final searchCopy = RemoteAssetFactory.create(id: 'asset-1');
+      final mergedCopy = searchCopy.copyWith(localId: 'local-1');
+
+      expect(searchCopy.localId, isNull);
+      expect(mergedCopy.localId, 'local-1');
+      expect(searchCopy.heroTag, isNot(mergedCopy.heroTag));
+
+      expect(searchCopy.isSameAsset(mergedCopy), isTrue);
+      expect(mergedCopy.isSameAsset(searchCopy), isTrue);
+    });
+
+    test('different remote assets are not the same', () {
+      final a = RemoteAssetFactory.create(id: 'asset-1');
+      final b = RemoteAssetFactory.create(id: 'asset-2');
+
+      expect(a.isSameAsset(b), isFalse);
+    });
+
+    test('same checksum but different remote ids are not the same (duplicate files)', () {
+      final a = RemoteAssetFactory.create(id: 'asset-1');
+      final b = RemoteAssetFactory.create(id: 'asset-2').copyWith(checksum: a.checksum);
+
+      expect(a.checksum, b.checksum);
+      expect(a.isSameAsset(b), isFalse);
+    });
+
+    test('falls back to checksum when only one side has an id (local-only vs remote-only)', () {
+      final remoteOnly = RemoteAssetFactory.create(id: 'asset-1');
+      final localOnly = LocalAssetFactory.create(id: 'local-1').copyWith(checksum: remoteOnly.checksum);
+
+      expect(remoteOnly.isSameAsset(localOnly), isTrue);
+      expect(localOnly.isSameAsset(remoteOnly), isTrue);
+    });
+  });
+}