First-visit users now always land on the English UI regardless of
navigator.language. Arabic remains one click away via the toggle, and
the user's explicit pick is persisted to localStorage (encoach-lang)
and honoured on every subsequent load.
- src/i18n/index.ts: set lng: "en", drop navigator/htmlTag from the
detector order so an Arabic-locale browser no longer silently boots
the UI in Arabic before the user has chosen.
- src/lib/api-client.ts: mirror the same policy for the Accept-Language
header sent to the backend, so AI-generated content stays English on
first visit instead of echoing the browser locale.
Made-with: Cursor