Netlify prebuild tests import the YouTube listing JSON at module load time, so a fresh checkout needs a baseline copy of that data before any generated API step runs. The fetched JSON is committed and explicitly unignored while the broader static/api output remains generated.
Constraint: Netlify runs test-prebuild before Astro generation creates generated API files
Rejected: Move all API generation before tests | broader build-order change with more external dependencies
Confidence: high
Scope-risk: narrow
Directive: Keep static/api/youtube-videos.json tracked unless helpers/site-listings.js stops importing it at module load time
Tested: pnpm run with-env vite-node /tmp/fetch-youtube-videos.mjs
Tested: pnpm run with-env vitest test/prebuild/site-listings.test.js
Tested: pnpm run netlify-prebuild:test-prebuild-functions
