Complete verification links and preserve verified login email (#60)

frontend/app/test/auth_test.dart

@@ -145,8 +145,8 @@ void main() {
         find.byKey(const ValueKey('verification-verified')),
         findsOneWidget,
       );
-      await tester.ensureVisible(find.text('Back to login'));
-      await tester.tap(find.text('Back to login'));
+      await tester.ensureVisible(find.text('Continue to login'));
+      await tester.tap(find.text('Continue to login'));
       await tester.pumpAndSettle();
       expect(find.byKey(const ValueKey('confirmation')), findsNothing);
       expect(find.text('example-password'), findsNothing);

frontend/app/test/routing_test.dart

@@ -42,6 +42,67 @@ Future<GoRouter> openRoute(
 }
 
 void main() {
+  for (final language in ['en', 'ru']) {
+    testWidgets(
+      'verified link keeps success visible and prefills login ($language)',
+      (tester) async {
+        tester.platformDispatcher.defaultRouteNameTestValue =
+            '/verify-email?token=demo-valid';
+        addTearDown(tester.platformDispatcher.clearDefaultRouteNameTestValue);
+        await tester.pumpWidget(
+          SxchngeApp(
+            localeProvider: LocaleProvider(initialLocale: Locale(language)),
+            verificationService: const DummyVerificationService(
+              delay: Duration.zero,
+              verifiedEmail: 'private-alias@example.com',
+            ),
+          ),
+        );
+        await tester.pumpAndSettle();
+        expect(
+          find.byKey(const ValueKey('verification-verified')),
+          findsOneWidget,
+        );
+        expect(find.byKey(const ValueKey('email')), findsNothing);
+        final router = GoRouter.of(
+          tester.element(find.byType(VerificationPage)),
+        );
+        expect(router.routeInformationProvider.value.uri.path, '/verify-email');
+        await tester.ensureVisible(
+          find.byKey(const ValueKey('verification-continue')),
+        );
+        await tester.tap(find.byKey(const ValueKey('verification-continue')));
+        await tester.pumpAndSettle();
+        final email = tester.widget<TextFormField>(
+          find.byKey(const ValueKey('email')),
+        );
+        expect(email.controller!.text, 'private-alias@example.com');
+        final password = tester.state<EditableTextState>(
+          find.descendant(
+            of: find.byKey(const ValueKey('password')),
+            matching: find.byType(EditableText),
+          ),
+        );
+        expect(password.currentTextEditingValue.text, isEmpty);
+        expect(password.widget.focusNode.hasFocus, isTrue);
+        expect(router.routeInformationProvider.value.uri.toString(), '/');
+        final restored = router.routeInformationParser.restoreRouteInformation(
+          router.routerDelegate.currentConfiguration,
+        )!;
+        expect(
+          restored.state.toString(),
+          isNot(contains('private-alias@example.com')),
+        );
+        expect(restored.state.toString(), isNot(contains('demo-valid')));
+        await tester.enterText(
+          find.byKey(const ValueKey('email')),
+          'changed@example.com',
+        );
+        expect(email.controller!.text, 'changed@example.com');
+        expect(find.byKey(const ValueKey('confirmation')), findsNothing);
+      },
+    );
+  }
   testWidgets('unknown deep link redirects to canonical login URL', (
     tester,
   ) async {