fix: add referral support + get referrerId from Telegram start_param in plans

app/plans/page.tsx

@@ -93,6 +93,19 @@ export default function PlansNew() {
   const [availableLocations, setAvailableLocations] = useState<Location[]>([]);
   const [isLoadingLocations, setIsLoadingLocations] = useState(false);
   const [isCreatingUser, setIsCreatingUser] = useState(false);
+  const [referrerId, setReferrerId] = useState<string | null>(null);
+
+  // Получаем referrerId из Telegram start_param при монтировании
+  useEffect(() => {
+    const telegramWebApp = (window as any).Telegram?.WebApp;
+    const startParam = telegramWebApp?.initDataUnsafe?.start_param;
+    
+    if (startParam && startParam.startsWith('ref_')) {
+      const refId = startParam.replace('ref_', '');
+      setReferrerId(refId);
+      console.log('🎁 Referral detected:', refId);
+    }
+  }, []);
 
   // Загрузить локации при переходе к шагу выбора
   useEffect(() => {
@@ -183,6 +196,7 @@ export default function PlansNew() {
         telegramUsername: user?.username || null,
         firstName: user?.first_name || null,
         lastName: user?.last_name || null,
+        referrerId: referrerId || null, // Добавляем referrerId
       };
       
       console.log('📤 REQUEST BODY:', requestBody);