AWS OIDC IDC/Builder-ID tokens omit profileArn, so CodeWhisperer calls
return 403 "User is not authorized". Resolve it natively via the
ListAvailableProfiles API instead of reading Kiro IDE profile.json.
- providers.js: add fetchKiroProfileArn() and resolve on poll (new logins)
- tokenRefresh.js: backfill profileArn on refresh so existing IDC
connections self-heal without re-login
Co-authored-by: Cursor <cursoragent@cursor.com>