refactor(auth): unify messenger bot link flow across login/profile/notifications

app/pages/notifications.vue

@@ -6,6 +6,7 @@ import {
   MyNotificationHistoryDocument,
   SendTestMessengerMessageDocument,
 } from '~/composables/graphql/generated';
+import { buildMessengerBotStartUrl } from '~/composables/useMessengerBotLink';
 
 const selectedChannel = ref<'TELEGRAM' | 'MAX'>('TELEGRAM');
 const customMessage = ref('Тест канала уведомлений Fregat');
@@ -55,9 +56,7 @@ function buildBotConnectUrl(baseUrl: string) {
     return '';
   }
 
-  const payload = encodeURIComponent(`login:${email}`);
-  const separator = baseUrl.includes('?') ? '&' : '?';
-  return `${baseUrl}${separator}start=${payload}`;
+  return buildMessengerBotStartUrl(baseUrl, email);
 }
 
 const telegramConnectUrl = computed(() => buildBotConnectUrl(config.public.telegramBotUrl || ''));