Error Handling

Handle errors, 404s, and loading states with special files.

Three special files in any route folder control non-happy-path UI:

• error.tsx — rendered when a page throws
• not-found.tsx — rendered for unmatched routes (404)
• loading.tsx — a skeleton shown while data resolves

export default function NotFound() {
  return <div><h1>404</h1><p>Page not found.</p></div>;
}