style(userfront): apply dart format

userfront/lib/core/services/auth_token_store_backend.dart

@@ -8,11 +8,7 @@ class AuthTokenStoreBackend {
   AuthTokenStoreBackend({
     required AuthTokenStorageTarget localTarget,
     required AuthTokenStorageTarget sessionTarget,
-  }) : _targets = [
-         localTarget,
-         sessionTarget,
-         _MemoryStorageTarget(),
-       ];
+  }) : _targets = [localTarget, sessionTarget, _MemoryStorageTarget()];
 
   static const _tokenKey = 'baron_auth_token';
   static const _providerKey = 'baron_auth_provider';

userfront/test/auth_token_store_backend_test.dart

@@ -5,7 +5,9 @@ void main() {
   group('AuthTokenStoreBackend', () {
     test('local 저장소가 실패하면 session 저장소에서 토큰을 읽는다', () {
       final local = _FakeTarget(throwsOnRead: true);
-      final session = _FakeTarget(readSeed: {'baron_auth_token': 'session-jwt'});
+      final session = _FakeTarget(
+        readSeed: {'baron_auth_token': 'session-jwt'},
+      );
       final store = AuthTokenStoreBackend(
         localTarget: local,
         sessionTarget: session,