The `locale` parameter passed to getRequestConfig is deprecated; next-intl now provides `requestLocale` as a Promise. Resolve it at the top of the callback, fall back to defaultLocale when the requested one isn't supported, and return both locale and messages. Removes the per-request deprecation warning in dev/E2E logs. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>