perf: add Zustand selectors to prevent cascading re-renders

Replace all bare useAuthStore(), useBlockingStore(), and
useSuccessNotification() calls with individual field selectors.
This prevents components from re-rendering when unrelated store
fields change.

- 21 useAuthStore usages across 20 files: individual selectors
  for 1-2 fields, useShallow for 3+ fields
- 5 useBlockingStore usages: individual selectors
- 2 useSuccessNotification usages: individual selectors

src/pages/Connection.tsx

@@ -14,7 +14,8 @@ import InstallationGuide from '../components/connection/InstallationGuide';
 export default function Connection() {
   const { t, i18n } = useTranslation();
   const navigate = useNavigate();
-  const { user, isAdmin } = useAuthStore();
+  const user = useAuthStore((state) => state.user);
+  const isAdmin = useAuthStore((state) => state.isAdmin);
   const { isTelegramWebApp } = useTelegramSDK();
   const { impact: hapticImpact } = useHaptic();