Fix: destructure setLanguage from useLanguage

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

studio-v2/app/parent/page.tsx

@@ -27,7 +27,7 @@ const parentT: Record<string, Record<string, string>> = {
 
 export default function ParentPage() {
   const { isDark } = useTheme()
-  const { language } = useLanguage()
+  const { language, setLanguage } = useLanguage()
   const [units, setUnits] = useState<LearningUnit[]>([])
   const [isLoading, setIsLoading] = useState(true)