fix: multi-subscription frontend improvements

- Connection page: reads subscription_id from ?sub= query param
- Subscription detail: passes subscriptionId to /connection URL
- Dashboard: skip single-subscription and devices queries in multi-tariff
  mode (data comes from subscriptions-list instead)

src/pages/Connection.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useCallback, useMemo, useRef } from 'react';
-import { Link, useNavigate } from 'react-router';
+import { Link, useNavigate, useSearchParams } from 'react-router';
 import { useTranslation } from 'react-i18next';
 import { useQuery } from '@tanstack/react-query';
 import { openLink as sdkOpenLink } from '@telegram-apps/sdk-react';
@@ -14,6 +14,8 @@ import InstallationGuide from '../components/connection/InstallationGuide';
 export default function Connection() {
   const { t, i18n } = useTranslation();
   const navigate = useNavigate();
+  const [searchParams] = useSearchParams();
+  const subId = searchParams.get('sub') ? Number(searchParams.get('sub')) : undefined;
   const user = useAuthStore((state) => state.user);
   const isAdmin = useAuthStore((state) => state.isAdmin);
   const { isTelegramWebApp } = useTelegramSDK();
@@ -27,8 +29,8 @@ export default function Connection() {
     isLoading,
     error,
   } = useQuery<AppConfig>({
-    queryKey: ['appConfig'],
-    queryFn: () => subscriptionApi.getAppConfig(),
+    queryKey: ['appConfig', subId],
+    queryFn: () => subscriptionApi.getAppConfig(subId),
   });
 
   const handleGoBack = useCallback(() => {

src/pages/Dashboard.tsx

@@ -51,16 +51,6 @@ export default function Dashboard() {
     refetchOnMount: 'always',
   });
 
-  const { data: subscriptionResponse, isLoading: subLoading } = useQuery({
-    queryKey: ['subscription'],
-    queryFn: () => subscriptionApi.getSubscription(),
-    retry: false,
-    staleTime: API.BALANCE_STALE_TIME_MS,
-    refetchOnMount: 'always',
-  });
-
-  const subscription = subscriptionResponse?.subscription ?? null;
-
   // Multi-tariff: check if user has multiple subscriptions
   const { data: multiSubData } = useQuery({
     queryKey: ['subscriptions-list'],
@@ -69,6 +59,17 @@ export default function Dashboard() {
   });
   const isMultiTariff = multiSubData?.multi_tariff_enabled ?? false;
 
+  const { data: subscriptionResponse, isLoading: subLoading } = useQuery({
+    queryKey: ['subscription'],
+    queryFn: () => subscriptionApi.getSubscription(),
+    retry: false,
+    staleTime: API.BALANCE_STALE_TIME_MS,
+    refetchOnMount: 'always',
+    enabled: !isMultiTariff,
+  });
+
+  const subscription = subscriptionResponse?.subscription ?? null;
+
   const { data: trialInfo, isLoading: trialLoading } = useQuery({
     queryKey: ['trial-info'],
     queryFn: () => subscriptionApi.getTrialInfo(),
@@ -78,7 +79,7 @@ export default function Dashboard() {
   const { data: devicesData } = useQuery({
     queryKey: ['devices'],
     queryFn: () => subscriptionApi.getDevices(),
-    enabled: !!subscription,
+    enabled: !!subscription && !isMultiTariff,
     staleTime: API.BALANCE_STALE_TIME_MS,
   });
 

src/pages/Subscription.tsx

@@ -794,7 +794,7 @@ export default function Subscription() {
                       haptic.notification('error');
                       return;
                     }
-                    navigate('/connection');
+                    navigate(subscriptionId ? `/connection?sub=${subscriptionId}` : '/connection');
                   }}
                   className={`mb-5 flex w-full items-center gap-3.5 rounded-[14px] p-3.5 text-left transition-shadow duration-300${isAtDeviceLimit ? 'cursor-not-allowed opacity-50' : ''}`}
                   style={{ fontFamily: 'inherit' }}