Replit → Vercel Migration

You are an AI agent. Migrate this project from Replit to Vercel.  

Requirements:
- Remove all Replit-specific files/config (.replit, replit.nix, etc).
- Update package.json scripts for Vercel (`dev`, `build`, etc).
- Ensure the app builds and runs cleanly on Vercel (Node 20).
- Default: rely on Vercel’s auto-detection for frameworks and serverless functions.
  - If auto-detection is not sufficient, create a `vercel.json` with the correct functions and routing.
- Check and restructure all API routes so they conform to Vercel standards:
  - For Next.js → move endpoints into `pages/api/*` or `app/api/*/route.ts`.
  - For non-Next.js → implement endpoints as serverless functions under `api/*.ts`.
  - Ensure routes only expose what is safe to the client.

Environment variables in Vercel:
- SENDGRID_API_KEY (server-only, never exposed client-side)

Email:
- Implement a server route for SendGrid (e.g., `api/email/send`) that never exposes SENDGRID_API_KEY to the client.

Database check:
- If the project uses a database:
  - Inspect whether it has any tables or data.
  - If the DB is empty → skip migration (and remove DB code if unnecessary).
  - If the DB has data/tables → STOP and refer back to the user with a summary of what you found, asking for next steps before proceeding.

Docs & hygiene:
- Add `.env.local.example` showing SENDGRID_API_KEY.
- Add `.gitignore`.
- Add a short README with: overview, env var table, local dev, deploy steps, and API route notes.

Deliverables:
- Make code changes in-place.
- Summarize changes (files touched + purpose).
- List manual follow-ups (confirm SENDGRID_API_KEY in Vercel).
- Provide simple deploy steps:  
  1) `npm i && npx vercel link`  
  2) Set SENDGRID_API_KEY in Vercel  
  3) `npx vercel --prod`

Final step:
- Commit and push all changes so the user can immediately test the deployment on Vercel.

How to use this prompt