Replace Telegram widget with bot login

lib/screens/mapflow_shell.dart

@@ -5,7 +5,9 @@ import 'package:flutter_map/flutter_map.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:latlong2/latlong.dart';
 
+import '../api/mapflow_api.dart';
 import '../auth/telegram_login_button.dart';
+import '../auth/telegram_session.dart' as telegram_session;
 import '../models/place_models.dart';
 import '../state/place_controller.dart';
 
@@ -179,11 +181,86 @@ class _UserAvatar extends StatelessWidget {
   }
 }
 
-class _TelegramLoginScreen extends StatelessWidget {
+class _TelegramLoginScreen extends StatefulWidget {
   const _TelegramLoginScreen({required this.onAuthenticated});
 
   final VoidCallback onAuthenticated;
 
+  @override
+  State<_TelegramLoginScreen> createState() => _TelegramLoginScreenState();
+}
+
+class _TelegramLoginScreenState extends State<_TelegramLoginScreen> {
+  final _api = MapflowApi();
+  Timer? _pollTimer;
+  var _loading = false;
+  var _message = '';
+
+  @override
+  void initState() {
+    super.initState();
+    final urlToken = telegram_session.telegramLoginTokenFromUrl();
+    final pendingToken = urlToken.isNotEmpty
+        ? urlToken
+        : telegram_session.pendingTelegramLoginToken();
+    if (pendingToken.isNotEmpty) {
+      telegram_session.savePendingTelegramLoginToken(pendingToken);
+      _pollLogin(pendingToken);
+      _pollTimer = Timer.periodic(
+        const Duration(seconds: 2),
+        (_) => _pollLogin(pendingToken),
+      );
+    }
+  }
+
+  @override
+  void dispose() {
+    _pollTimer?.cancel();
+    super.dispose();
+  }
+
+  Future<void> _startLogin() async {
+    setState(() {
+      _loading = true;
+      _message = '';
+    });
+    final login = await _api.startTelegramBotLogin();
+    telegram_session.savePendingTelegramLoginToken(login.token);
+    telegram_session.openExternalUrl(login.botUrl);
+    _pollTimer?.cancel();
+    _pollTimer = Timer.periodic(
+      const Duration(seconds: 2),
+      (_) => _pollLogin(login.token),
+    );
+    setState(() {
+      _loading = false;
+      _message = 'Подтверди вход в боте.';
+    });
+  }
+
+  Future<void> _pollLogin(String token) async {
+    final status = await _api.fetchTelegramBotLoginStatus(token);
+    if (status.isExpired) {
+      _pollTimer?.cancel();
+      telegram_session.clearPendingTelegramLoginToken();
+      if (!mounted) {
+        return;
+      }
+      setState(() => _message = 'Ссылка устарела. Запусти вход заново.');
+      return;
+    }
+
+    if (!status.isConfirmed) {
+      return;
+    }
+
+    _pollTimer?.cancel();
+    telegram_session.saveMapflowSessionToken(status.sessionToken!);
+    telegram_session.clearPendingTelegramLoginToken();
+    widget.onAuthenticated();
+    telegram_session.reloadApp();
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -202,7 +279,15 @@ class _TelegramLoginScreen extends StatelessWidget {
                   ),
                 ),
                 const SizedBox(height: 24),
-                TelegramLoginButton(onAuthenticated: onAuthenticated),
+                TelegramLoginButton(onPressed: _startLogin, loading: _loading),
+                if (_message.isNotEmpty) ...[
+                  const SizedBox(height: 14),
+                  Text(
+                    _message,
+                    textAlign: TextAlign.center,
+                    style: Theme.of(context).textTheme.bodyMedium,
+                  ),
+                ],
               ],
             ),
           ),