🐛(frontend) restore user language synchronization between front and back

Fix issue where user language preferences stopped properly syncing between
frontend and backend, causing inconsistent language experience. Issue was
reported by user and affected localization settings persistence.

src/frontend/src/components/AppInitialization.tsx

@@ -2,9 +2,11 @@ import { silenceLiveKitLogs } from '@/utils/livekit'
 import { useConfig } from '@/api/useConfig'
 import { useAnalytics } from '@/features/analytics/hooks/useAnalytics'
 import { useSupport } from '@/features/support/hooks/useSupport'
+import { useSyncUserPreferencesWithBackend } from '@/features/auth'
 
 export const AppInitialization = () => {
   const { data } = useConfig()
+  useSyncUserPreferencesWithBackend()
 
   const {
     analytics = {},