fix(domain): fall back to unsuffixed API_URL in EnvConfig.apiUrl

modules/domain/lib/env/env_config.dart

@@ -9,5 +9,10 @@ class EnvConfig {
 
   static String get envConfigFile => 'env/.env.example';
 
-  static String get apiUrl => dotenv.env['API_URL_$env']?.toString() ?? '';
+  /// Supports both env file layouts:
+  /// - one file per flavor (e.g. `env/.dev`) with an unsuffixed `API_URL`;
+  /// - a single file with suffixed keys (`API_URL_DEV`, `API_URL_QA`,
+  ///   `API_URL_PROD`) as in `env/.env.example`. A suffixed key wins.
+  static String get apiUrl =>
+      dotenv.env['API_URL_$env'] ?? dotenv.env['API_URL'] ?? '';
 }

modules/domain/test/env/env_config_test.dart

@@ -0,0 +1,42 @@
+import 'package:domain/env/env_config.dart';
+import 'package:flutter_dotenv/flutter_dotenv.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  tearDown(() => EnvConfig.env = EnvConfig.kDevEnv);
+
+  group('EnvConfig.apiUrl', () {
+    test('reads the unsuffixed API_URL of a per-flavor file', () {
+      dotenv.testLoad(fileInput: 'API_URL=https://dev.example.com');
+      EnvConfig.env = EnvConfig.kDevEnv;
+
+      expect(EnvConfig.apiUrl, 'https://dev.example.com');
+    });
+
+    test('reads the key suffixed with the active flavor', () {
+      dotenv.testLoad(
+        fileInput: 'API_URL_DEV=https://dev.example.com\n'
+            'API_URL_QA=https://qa.example.com',
+      );
+      EnvConfig.env = EnvConfig.kQaEnv;
+
+      expect(EnvConfig.apiUrl, 'https://qa.example.com');
+    });
+
+    test('prefers the suffixed key over the unsuffixed one', () {
+      dotenv.testLoad(
+        fileInput: 'API_URL=https://fallback.example.com\n'
+            'API_URL_PROD=https://prod.example.com',
+      );
+      EnvConfig.env = EnvConfig.kProdEnv;
+
+      expect(EnvConfig.apiUrl, 'https://prod.example.com');
+    });
+
+    test('is empty when no API_URL key is defined', () {
+      dotenv.testLoad(fileInput: 'ENV=dev');
+
+      expect(EnvConfig.apiUrl, isEmpty);
+    });
+  });
+}