const constructure

lib/infrastructure/category/datasources/local_data_provider.dart

@@ -17,7 +17,9 @@ class CategoryLocalDataProvider {
   CategoryLocalDataProvider(this._databaseHelper);
 
   final Map<String, List<CategoryDto>> _queryCache = {};
-  final Duration _cacheExpiry = Duration(minutes: AppConstant.cacheExpire);
+  final Duration _cacheExpiry = const Duration(
+    minutes: AppConstant.cacheExpire,
+  );
   final Map<String, DateTime> _cacheTimestamps = {};
 
   Future<DC<CategoryFailure, void>> saveCategoriesBatch(
@@ -203,7 +205,7 @@ class CategoryLocalDataProvider {
 
       if (maps.isEmpty) {
         log('❌ Category not found: $id', name: _logName);
-        return DC.error(CategoryFailure.empty());
+        return DC.error(const CategoryFailure.empty());
       }
 
       final category = CategoryDto.fromMap(maps.first);

lib/infrastructure/category/datasources/remote_data_provider.dart

@@ -29,7 +29,7 @@ class CategoryRemoteDataProvider {
       );
 
       if (response.data['data'] == null) {
-        return DC.error(CategoryFailure.empty());
+        return DC.error(const CategoryFailure.empty());
       }
 
       final categories = ListCategoryDto.fromJson(