useNativeLanguage: Now has setNativeLang() that persists to localStorage.
Language selection carries across all pages automatically.
LanguageSwitcher: Compact dropdown component added to learn/layout.tsx
and parent/layout.tsx — visible on every sub-page (top-right).
Parent portal: Language dropdown syncs both UI language and native
language. Parents can switch language mid-session (e.g. when both
parents speak different languages).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
