fix(auth): 登录异常改为居中吐司

test/auth/auth_page_test.dart

@@ -78,7 +78,7 @@ void main() {
 
     expect(find.text('Enter your email'), findsOneWidget);
     expect(find.text('Welcome back'), findsOneWidget);
-    expect(find.byKey(const Key('centered-error-dialog')), findsNothing);
+    expect(find.byKey(const Key('centered-toast')), findsNothing);
   });
 
   testWidgets(
@@ -95,11 +95,11 @@ void main() {
         find.text('Password needs both letters and numbers'),
         findsOneWidget,
       );
-      expect(find.byKey(const Key('centered-error-dialog')), findsNothing);
+      expect(find.byKey(const Key('centered-toast')), findsNothing);
     },
   );
 
-  testWidgets('should_show_centered_dialog_when_login_api_returns_an_error', (
+  testWidgets('should_show_centered_toast_when_login_api_returns_an_error', (
     tester,
   ) async {
     final api = _FailingAuthApi(loginMessage: 'Invalid email or password');
@@ -110,13 +110,13 @@ void main() {
     await tester.tap(find.byKey(const Key('auth-submit')));
     await tester.pumpAndSettle();
 
-    final dialog = find.byKey(const Key('centered-error-dialog'));
-    expect(dialog, findsOneWidget);
-    expect(find.text('Login failed'), findsOneWidget);
+    final toast = find.byKey(const Key('centered-toast'));
+    expect(toast, findsOneWidget);
     expect(find.text('Invalid email or password'), findsOneWidget);
+    expect(find.byType(AlertDialog), findsNothing);
     expect(api.loginCalls, 1);
     expect(
-      tester.getCenter(dialog),
+      tester.getCenter(toast),
       offsetMoreOrLessEquals(
         tester.getCenter(find.byType(Scaffold)),
         epsilon: 1,
@@ -129,32 +129,29 @@ void main() {
       isNotNull,
     );
 
-    await tester.tap(find.byKey(const Key('centered-error-confirm')));
-    await tester.pumpAndSettle();
-    expect(dialog, findsNothing);
+    await _pumpToastAway(tester);
+    expect(toast, findsNothing);
   });
 
-  testWidgets(
-    'should_show_registration_failed_title_when_register_api_returns_an_error',
-    (tester) async {
-      final api = _FailingAuthApi(registerMessage: 'Email already exists');
-      await pumpAuthPage(tester, signUp: true, api: api);
-      await _enterValidCredentials(tester);
+  testWidgets('should_show_centered_toast_when_register_api_returns_an_error', (
+    tester,
+  ) async {
+    final api = _FailingAuthApi(registerMessage: 'Email already exists');
+    await pumpAuthPage(tester, signUp: true, api: api);
+    await _enterValidCredentials(tester);
 
-      await tester.ensureVisible(find.byKey(const Key('auth-submit')));
-      await tester.tap(find.byKey(const Key('auth-submit')));
-      await tester.pumpAndSettle();
+    await tester.ensureVisible(find.byKey(const Key('auth-submit')));
+    await tester.tap(find.byKey(const Key('auth-submit')));
+    await tester.pumpAndSettle();
 
-      expect(find.byKey(const Key('centered-error-dialog')), findsOneWidget);
-      expect(find.text('Registration failed'), findsOneWidget);
-      expect(find.text('Email already exists'), findsOneWidget);
-      expect(api.registerCalls, 1);
+    expect(find.byKey(const Key('centered-toast')), findsOneWidget);
+    expect(find.text('Email already exists'), findsOneWidget);
+    expect(find.byType(AlertDialog), findsNothing);
+    expect(api.registerCalls, 1);
 
-      await tester.tapAt(const Offset(8, 8));
-      await tester.pumpAndSettle();
-      expect(find.byKey(const Key('centered-error-dialog')), findsNothing);
-    },
-  );
+    await _pumpToastAway(tester);
+    expect(find.byKey(const Key('centered-toast')), findsNothing);
+  });
 
   testWidgets(
     'should_show_network_error_when_login_throws_an_unknown_exception',
@@ -167,8 +164,12 @@ void main() {
       await tester.tap(find.byKey(const Key('auth-submit')));
       await tester.pumpAndSettle();
 
-      expect(find.byKey(const Key('centered-error-dialog')), findsOneWidget);
+      expect(find.byKey(const Key('centered-toast')), findsOneWidget);
       expect(find.text('Network error, please try again'), findsOneWidget);
+      expect(find.byType(AlertDialog), findsNothing);
+
+      await _pumpToastAway(tester);
+      expect(find.byKey(const Key('centered-toast')), findsNothing);
     },
   );
 
@@ -422,6 +423,11 @@ Future<void> _enterValidCredentials(WidgetTester tester) async {
   await tester.enterText(find.byKey(const Key('auth-password')), 'abcd1234');
 }
 
+Future<void> _pumpToastAway(WidgetTester tester) async {
+  await tester.pump(const Duration(seconds: 3));
+  await tester.pumpAndSettle();
+}
+
 void _expectAboveKeyboard(WidgetTester tester, Key fieldKey, double inset) {
   final screenHeight =
       tester.view.physicalSize.height / tester.view.devicePixelRatio;