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>
useNativeLanguage.ts: Hook that reads bp_native_language from
localStorage and provides t(key) for translated UI text and
wordInNative() for vocabulary translations.
exerciseTranslations.ts: All exercise UI strings in DE/EN/TR/AR/UK/RU/PL.
Buttons (Richtig/Falsch), instructions, labels, result texts.
Next: Wire into all 9 exercise pages for trilingual display.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
