test: add fake token storage implementation for testing purposes

flutter/test/features/profile/data/profile_repository_test.dart

@@ -2,6 +2,8 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:recipe_flutter/core/api/api_client.dart';
 import 'package:recipe_flutter/core/api/api_exception.dart';
+import 'package:recipe_flutter/core/platform/platform_providers.dart';
+import 'package:recipe_flutter/core/platform/token_storage.dart';
 import 'package:recipe_flutter/features/profile/data/profile_repository.dart';
 import 'package:recipe_flutter/features/profile/domain/user_profile.dart';
 
@@ -32,6 +34,20 @@ class _FakeApiClient extends ApiClient {
   }
 }
 
+/// In-memory token storage — no platform channels, no SharedPreferences.
+class _FakeTokenStorage implements ITokenStorage {
+  String? _token;
+
+  @override
+  Future<String?> getToken() async => _token;
+
+  @override
+  Future<void> saveToken(String token) async => _token = token;
+
+  @override
+  Future<void> deleteToken() async => _token = null;
+}
+
 void main() {
   late _FakeApiClient fakeClient;
   late ProviderContainer container;
@@ -48,7 +64,10 @@ void main() {
   setUp(() {
     fakeClient = _FakeApiClient();
     container = ProviderContainer(
-      overrides: [apiClientProvider.overrideWithValue(fakeClient)],
+      overrides: [
+        apiClientProvider.overrideWithValue(fakeClient),
+        tokenStorageProvider.overrideWithValue(_FakeTokenStorage()),
+      ],
     );
     repo = container.read(profileRepositoryProvider);
   });