- Split monolithic i18n.js into per-language files under js/i18n/
- Lazy-load translations via dynamic import() with caching
- Add French (fr) language support
- Add error handling in _loadLang with English fallback
- Remove duplicated lang.name from per-language files (registry is single source of truth)
- Add dev-time key validation (warns on localhost when keys are missing vs en.js)
- Add missing alerts.fileTooLarge key from main to all language files
- Await async initLang() in main.js (supported by type=module)