feat(category): add autocomplete for category inputs

lib/presentation/providers/restaurant_provider.dart

@@ -241,14 +241,14 @@ final searchQueryProvider = StateProvider<String>((ref) => '');
 final selectedCategoryProvider = StateProvider<String?>((ref) => null);
 
 /// 필터링된 맛집 목록 Provider (검색 + 카테고리)
-final filteredRestaurantsProvider = StreamProvider<List<Restaurant>>((
+final filteredRestaurantsProvider = Provider<AsyncValue<List<Restaurant>>>((
   ref,
-) async* {
+) {
   final searchQuery = ref.watch(searchQueryProvider);
   final selectedCategory = ref.watch(selectedCategoryProvider);
-  final restaurantsStream = ref.watch(restaurantListProvider.stream);
+  final restaurantsAsync = ref.watch(restaurantListProvider);
 
-  await for (final restaurants in restaurantsStream) {
+  return restaurantsAsync.whenData((restaurants) {
     var filtered = restaurants;
 
     // 검색 필터 적용
@@ -280,6 +280,6 @@ final filteredRestaurantsProvider = StreamProvider<List<Restaurant>>((
       }).toList();
     }
 
-    yield filtered;
-  }
+    return filtered;
+  });
 });