Two boundaries share the same content: src/app/not-found.tsx catches
genuinely unmatched URLs (rendered bare in the root layout), and
(app)/not-found.tsx catches notFound() calls from within app routes
(already used by scripts/[scriptId] and runs/[runId]) so it renders
nested inside AppLayout, keeping nav and footer visible.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
