fix: no redundant search queries

lib/screens/search_screen.dart

@@ -28,6 +28,7 @@ class _SearchScreenState extends State<SearchScreen>
   bool _isSearching = false;
   bool _hasSearched = false;
   Timer? _debounceTimer;
+  String _lastSearchedQuery = '';
 
   @override
   void initState() {
@@ -54,10 +55,16 @@ class _SearchScreenState extends State<SearchScreen>
         _searchResults = [];
         _hasSearched = false;
         _isSearching = false;
+        _lastSearchedQuery = '';
       });
       return;
     }
 
+    // Only search if the query has actually changed
+    if (query.trim() == _lastSearchedQuery.trim()) {
+      return;
+    }
+
     // Start new timer
     _debounceTimer = Timer(const Duration(milliseconds: 500), () {
       _performSearch(query);
@@ -84,6 +91,7 @@ class _SearchScreenState extends State<SearchScreen>
         setState(() {
           _searchResults = results;
           _isSearching = false;
+          _lastSearchedQuery = query.trim();
         });
       }
     } catch (e) {