Replace Telegram widget with bot login

lib/auth/telegram_session_web.dart

@@ -3,6 +3,8 @@ import 'dart:js_interop';
 import 'package:web/web.dart' as web;
 
 const telegramLoginStorageKey = 'mapflow.telegramLoginData';
+const mapflowSessionStorageKey = 'mapflow.sessionToken';
+const pendingTelegramLoginStorageKey = 'mapflow.pendingTelegramLoginToken';
 
 @JS('window.Telegram.WebApp.initData')
 external JSString? get _telegramInitData;
@@ -15,7 +17,38 @@ String telegramInitData() => _telegramInitData?.toDart ?? '';
 String telegramLoginData() =>
     web.window.localStorage.getItem(telegramLoginStorageKey) ?? '';
 
+String mapflowSessionToken() =>
+    web.window.localStorage.getItem(mapflowSessionStorageKey) ?? '';
+
+String pendingTelegramLoginToken() =>
+    web.window.localStorage.getItem(pendingTelegramLoginStorageKey) ?? '';
+
+String telegramLoginTokenFromUrl() {
+  final uri = Uri.parse(web.window.location.href);
+  return uri.queryParameters['telegram_login'] ?? '';
+}
+
 void saveTelegramLoginData(JSAny? user) {
   final encoded = _jsonStringify(user).toDart;
   web.window.localStorage.setItem(telegramLoginStorageKey, encoded);
 }
+
+void saveMapflowSessionToken(String token) {
+  web.window.localStorage.setItem(mapflowSessionStorageKey, token);
+}
+
+void savePendingTelegramLoginToken(String token) {
+  web.window.localStorage.setItem(pendingTelegramLoginStorageKey, token);
+}
+
+void clearPendingTelegramLoginToken() {
+  web.window.localStorage.removeItem(pendingTelegramLoginStorageKey);
+}
+
+void openExternalUrl(String url) {
+  web.window.open(url, '_blank', 'noopener,noreferrer');
+}
+
+void reloadApp() {
+  web.window.location.assign(web.window.location.origin);
+}