- docs/guides/CODEX-CLI-CONFIGURATION.md was missing the YAML frontmatter
block required by fumadocs (title/version/lastUpdated), causing the
production build to fail with "invalid frontmatter" MDX error.
- CodexCliGuideModal.tsx called setLoading/setError synchronously in a
useEffect body, triggering the react-hooks/set-state-in-effect lint error.
Refactored to an internal async function with an `cancelled` guard to
prevent state updates on unmounted components.