Wire repo-root vercel.json so policybench.org auto-deploys

[MaxGhenis]

Why

Domain policybench.org is now bound to the policybench-site Vercel project (the legacy app and misconfigured policybench projects are gone). That project's rootDirectory is unset, so git auto-deploys try to build from repo root and find no Next.js app.

This adds a repo-root vercel.json that drives the build into app/:

• framework: nextjs
• buildCommand: cd app && bun install --frozen-lockfile && bun run build
• outputDirectory: app/.next

Result: pushing to main triggers a Vercel build that produces the same output as running bun run build inside app/ locally, and the production deploy auto-promotes to policybench.org.

Verification

• Vercel preview build for this PR will validate the config end-to-end.
• After merge, the next push should land on policybench.org automatically with no manual vercel --prod step.

🤖 Generated with Claude Code

[vercel]

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Project	Deployment	Actions	Updated (UTC)
policybench-site	Error		May 9, 2026 1:10am

[MaxGhenis]

Approach didn't work: Vercel runs framework detection from rootDirectory before buildCommand, so it errors out trying to find 'next' in the repo-root package.json. The right fix is to set rootDirectory = 'app' in the policybench-site project's Vercel dashboard settings — that's a one-toggle change but isn't exposed via CLI/API without a personal access token.