描述
Add, fix, audit, and maintain Flutter internationalization with gen-l10n, ARB files, AppLocalizations, flutter_localizations, intl formatting, plural/select messages, RTL support, locale-specific number/date formatting, and localization build errors. Use when asked to add l10n or i18n, translate Flutter UI text, configure l10n.yaml, manage ARB translations, migrate away from package:flutter_gen imports, or troubleshoot generated localization code.