Source Code added

mobile/lib/routing/gallery_guard.dart

@@ -0,0 +1,34 @@
+import 'dart:async';
+
+import 'package:auto_route/auto_route.dart';
+import 'package:immich_mobile/routing/router.dart';
+
+/// Handles duplicate navigation to this route (primarily for deep linking)
+class GalleryGuard extends AutoRouteGuard {
+  const GalleryGuard();
+  @override
+  void onNavigation(NavigationResolver resolver, StackRouter router) async {
+    final newRouteName = resolver.route.name;
+    final currentTopRouteName = router.stack.isNotEmpty ? router.stack.last.name : null;
+
+    if (currentTopRouteName == newRouteName) {
+      // Replace instead of pushing duplicate
+      final args = resolver.route.args as GalleryViewerRouteArgs;
+
+      unawaited(
+        router.replace(
+          GalleryViewerRoute(
+            renderList: args.renderList,
+            initialIndex: args.initialIndex,
+            heroOffset: args.heroOffset,
+            showStack: args.showStack,
+          ),
+        ),
+      );
+      // Prevent further navigation since we replaced the route
+      resolver.next(false);
+      return;
+    }
+    resolver.next(true);
+  }
+}