Adds i18next, LanguageDetector, locales (en.json, ar.json), and LanguageSwitcher component for internationalization. Replit-Commit-Author: Agent Replit-Commit-Session-Id: ff0be73b-afdd-4747-978b-bb8301fb0a82 Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/9777c70b-fc38-4831-8d6b-78dfffe041b0/d552135c-0e60-4fc7-98a2-0e9cddf2b4b3.jpg