Vercel's 'Skip deployments when no changes' feature treats files
outside workspace packages (e.g. browser_tests/, src/) as global
changes, triggering website preview builds on every PR.
- Add GitHub Action with paths filter scoped to apps/website/,
packages/design-system/, and packages/tailwind-utils/
- Add vercel.json to disable Vercel's automatic GitHub integration
- Preview deployments only trigger when website-relevant files change
- Production deployments trigger on push to main
Requires adding VERCEL_TOKEN, VERCEL_ORG_ID, and
VERCEL_WEBSITE_PROJECT_ID to GitHub repo secrets.