create promocode page

lib/data/repositories/promo_code_repository_impl.dart

@@ -0,0 +1,23 @@
+import '../../domain/entities/promo_code_result.dart';
+import '../../domain/repositories/promo_code_repository.dart';
+import '../models/promo_code_response_dto.dart';
+import '../network/api_service.dart';
+
+class PromoCodeRepositoryImpl implements PromoCodeRepository {
+  final ApiService apiService;
+
+  PromoCodeRepositoryImpl(this.apiService);
+
+  @override
+  Future<PromoCodeResult> applyPromoCode(String code) async {
+    try {
+      final data = await apiService.applyPromoCode(code);
+      final dto = PromoCodeResponseDto.fromJson(data);
+      return dto.toEntity();
+    } on PromoCodeNotFoundException {
+      throw Exception('Промокод не найден');
+    } catch (e) {
+      throw Exception('Ошибка активации промокода: $e');
+    }
+  }
+}