fix: promocode multi-tariff support in cabinet

- Balance page: handle select_subscription response — show subscription
  picker when promo code adds days and user has multiple tariffs
- API: activatePromocode now accepts optional subscriptionId
- AdminPromocodeCreate: show trial tariff info when creating
  trial_subscription promo code, warn if no trial tariff configured

src/api/balance.ts

@@ -68,14 +68,21 @@ export const balanceApi = {
   // Activate promo code
   activatePromocode: async (
     code: string,
+    subscriptionId?: number,
   ): Promise<{
     success: boolean;
-    message: string;
+    message?: string;
-    balance_before: number;
+    balance_before?: number;
-    balance_after: number;
+    balance_after?: number;
-    bonus_description: string | null;
+    bonus_description?: string | null;
+    error?: string;
+    eligible_subscriptions?: Array<{ id: number; tariff_name: string; days_left: number }>;
+    code?: string;
   }> => {
-    const response = await apiClient.post('/cabinet/promocode/activate', { code });
+    const response = await apiClient.post('/cabinet/promocode/activate', {
+      code,
+      ...(subscriptionId ? { subscription_id: subscriptionId } : {}),
+    });
     return response.data;
   },
 

src/pages/AdminPromocodeCreate.tsx

@@ -11,6 +11,7 @@ import {
   PromoCodeUpdateRequest,
   PromoGroup,
 } from '../api/promocodes';
+import { tariffsApi } from '../api/tariffs';
 import { usePlatform } from '../platform/hooks/usePlatform';
 
 // Icons
@@ -69,6 +70,15 @@ export default function AdminPromocodeCreate() {
 
   const promoGroups: PromoGroup[] = promoGroupsData?.items || [];
 
+  // Fetch tariffs to show trial tariff info
+  const { data: tariffsData } = useQuery({
+    queryKey: ['admin-tariffs-for-promo'],
+    queryFn: () => tariffsApi.getTariffs(true),
+    enabled: type === 'trial_subscription',
+  });
+
+  const trialTariff = tariffsData?.tariffs?.find((t) => t.is_trial_available) || null;
+
   // Fetch promocode for editing
   const { isLoading: isLoadingPromocode } = useQuery({
     queryKey: ['admin-promocode', id],
@@ -301,6 +311,31 @@ export default function AdminPromocodeCreate() {
           </div>
         )}
 
+        {type === 'trial_subscription' && (
+          <div className="rounded-lg border border-dark-600 bg-dark-700/50 p-3">
+            {trialTariff ? (
+              <div className="text-sm">
+                <span className="text-dark-400">
+                  {t('admin.promocodes.form.trialTariffInfo', 'Будет выдан тариф:')}
+                </span>{' '}
+                <span className="font-medium text-accent-400">{trialTariff.name}</span>
+                <span className="text-dark-500">
+                  {' '}
+                  ({trialTariff.traffic_limit_gb} GB, {trialTariff.device_limit}{' '}
+                  {t('admin.promocodes.form.devices', 'устр.')})
+                </span>
+              </div>
+            ) : (
+              <div className="text-sm text-warning-400">
+                {t(
+                  'admin.promocodes.form.noTrialTariff',
+                  '⚠️ Триальный тариф не настроен. Отметьте тариф как «доступен для триала» в настройках тарифов.',
+                )}
+              </div>
+            )}
+          </div>
+        )}
+
         {type === 'promo_group' && (
           <div>
             <label className="mb-2 block text-sm font-medium text-dark-300">

src/pages/Balance.tsx

@@ -80,6 +80,12 @@ export default function Balance() {
     message: string;
     amount: number;
   } | null>(null);
+  const [promoSelectSubs, setPromoSelectSubs] = useState<Array<{
+    id: number;
+    tariff_name: string;
+    days_left: number;
+  }> | null>(null);
+  const [promoSelectCode, setPromoSelectCode] = useState<string | null>(null);
   const [transactionsPage, setTransactionsPage] = useState(1);
   const [isHistoryOpen, setIsHistoryOpen] = useState(false);
 
@@ -135,27 +141,38 @@ export default function Balance() {
     }
   };
 
-  const handlePromocodeActivate = async () => {
+  const handlePromocodeActivate = async (subscriptionId?: number) => {
-    if (!promocode.trim()) return;
+    const code = subscriptionId ? promoSelectCode || '' : promocode.trim();
+    if (!code) return;
 
     setPromocodeLoading(true);
     setPromocodeError(null);
     setPromocodeSuccess(null);
 
     try {
-      const result = await balanceApi.activatePromocode(promocode.trim());
+      const result = await balanceApi.activatePromocode(code, subscriptionId);
+
+      if (result.error === 'select_subscription' && result.eligible_subscriptions) {
+        setPromoSelectSubs(result.eligible_subscriptions);
+        setPromoSelectCode(result.code || code);
+        return;
+      }
+
       if (result.success) {
-        const bonusAmount = result.balance_after - result.balance_before;
+        const bonusAmount = (result.balance_after || 0) - (result.balance_before || 0);
         setPromocodeSuccess({
           message: result.bonus_description || t('balance.promocode.success'),
           amount: bonusAmount,
         });
         setTransactionsPage(1);
         setPromocode('');
+        setPromoSelectSubs(null);
+        setPromoSelectCode(null);
         await refetchBalance();
         await refreshUser();
         queryClient.invalidateQueries({ queryKey: ['transactions'] });
         queryClient.invalidateQueries({ queryKey: ['purchase-options'] });
+        queryClient.invalidateQueries({ queryKey: ['subscriptions-list'] });
       }
     } catch (error: unknown) {
       const axiosError = error as { response?: { data?: { detail?: string } } };
@@ -170,6 +187,8 @@ export default function Balance() {
               ? 'already_used_by_user'
               : 'server_error';
       setPromocodeError(t(`balance.promocode.errors.${errorKey}`));
+      setPromoSelectSubs(null);
+      setPromoSelectCode(null);
     } finally {
       setPromocodeLoading(false);
     }
@@ -214,7 +233,7 @@ export default function Balance() {
               disabled={promocodeLoading}
             />
             <Button
-              onClick={handlePromocodeActivate}
+              onClick={() => handlePromocodeActivate()}
               disabled={!promocode.trim()}
               loading={promocodeLoading}
             >
@@ -250,6 +269,39 @@ export default function Balance() {
               </motion.div>
             )}
           </AnimatePresence>
+          {promoSelectSubs && promoSelectSubs.length > 0 && (
+            <motion.div
+              initial={{ opacity: 0, y: -10 }}
+              animate={{ opacity: 1, y: 0 }}
+              className="mt-3 space-y-2 rounded-linear border border-accent-500/30 bg-accent-500/10 p-3"
+            >
+              <div className="text-sm font-medium text-dark-200">
+                {t('balance.promocode.selectSubscription', 'К какой подписке применить промокод?')}
+              </div>
+              {promoSelectSubs.map((sub) => (
+                <button
+                  key={sub.id}
+                  onClick={() => handlePromocodeActivate(sub.id)}
+                  disabled={promocodeLoading}
+                  className="flex w-full items-center justify-between rounded-linear border border-dark-600 bg-dark-700 px-3 py-2 text-sm text-dark-200 transition-colors hover:border-accent-500/50 hover:bg-dark-600"
+                >
+                  <span>{sub.tariff_name}</span>
+                  <span className="text-dark-400">
+                    {t('balance.promocode.daysLeft', '{{count}} дн.', { count: sub.days_left })}
+                  </span>
+                </button>
+              ))}
+              <button
+                onClick={() => {
+                  setPromoSelectSubs(null);
+                  setPromoSelectCode(null);
+                }}
+                className="text-xs text-dark-400 hover:text-dark-200"
+              >
+                {t('common.cancel', 'Отмена')}
+              </button>
+            </motion.div>
+          )}
         </Card>
       </motion.div>