Supabase + Vercel Specialist Needed to Complete Isolated Next.js Beta Deployment

I need an experienced Supabase/Vercel deployment specialist to complete a tightly controlled beta infrastructure setup for an existing private Next.js application. The application code is already built and validated. This engagement is limited to database connectivity, migrations, Vercel configuration, deployment, and beta smoke testing. It is not a development or redesign project. **Current environment** - Next.js 16 application - Node.js with `pg` - Private GitHub repository - Dedicated Supabase beta project - Dedicated Vercel beta project - Supabase Session pooler intended for migrations - Supabase Transaction pooler intended for the Vercel serverless runtime - Access mode must remain `ACCESS_CODE_ONLY` - Application-side database pool is already limited to one connection - Trusted Supabase CA certificate is available - Source commit has passed 265/265 tests, migrations in CI, typecheck, lint, and production build **Current blocker** The local migration process reaches Supabase securely using verified TLS but receives PostgreSQL authentication error `28P01`. The database password has been reset, but authentication still needs to be diagnosed. No migration SQL has executed against the beta database. **Required work** 1. Verify the correct Supabase beta Session pooler username, host, database, and authentication configuration. 2. Run the repository’s existing migration process against the empty beta database. 3. Verify migration completion and schema state. 4. Correctly configure the Vercel beta project’s `DATABASE_URL` using the Transaction pooler. 5. Confirm required beta-only environment variables without exposing their values. 6. Reconnect the private GitHub repository only when deployment is ready. 7. Deploy the approved commit from `main`. 8. Perform controlled beta smoke testing. 9. Provide a concise written handoff documenting configuration names, migration results, deployed commit, deployment URL, and smoke-test results. **Strict boundaries** - No production database, secrets, DNS, or resources may be accessed or changed. - No custom domain configuration. - No live Stripe credentials or Stripe implementation. - No application-source changes without my explicit written approval. - No migration edits, destructive database actions, data imports, restores, or unapproved seeds. - Checkout must remain unavailable. - Secrets will not be shared through Upwork messages. - Work involving credentials must be completed by screen share while I enter the credentials myself. - Stop immediately and report if migrations fail, a source change appears necessary, Checkout becomes available, or any production resource appears accessible. **Required experience** Please apply only if you have direct experience with: - Supabase PostgreSQL - Supavisor Session and Transaction poolers - Node.js `pg` - PostgreSQL migrations - TLS/CA certificate troubleshooting - Vercel environment variables and private GitHub deployments - Next.js serverless deployment Please explain one similar Supabase/Vercel deployment you have completed and how you would troubleshoot PostgreSQL error `28P01` without requesting the database password through chat.