Add nodemon.json for full hot-reload (backend + frontend)

nodemon now watches both server.js and client/src/. On any change,
it rebuilds the React app and restarts Express — so git push makes
both backend AND frontend changes visible on the hot domain.

- dev script simplified to "nodemon" (reads nodemon.json config)
- dev:local added for human developers who want Vite HMR

README.md

@@ -36,9 +36,12 @@ React + shadcn/ui + Express + PostgreSQL + Redis scaffold for SAAC deployment.
 # Install all dependencies (postinstall auto-installs client deps)
 npm install
 
-# Run backend + frontend concurrently (nodemon + Vite HMR)
+# Run in dev mode (watches server.js + client/src, auto-rebuilds on changes)
 npm run dev
 
+# Or for local development with Vite HMR (browser hot-reload):
+npm run dev:local    # Express :3000 + Vite :5173 concurrently
+
 # Or run separately:
 npm run dev:server   # Express on :3000 (with nodemon auto-restart)
 npm run dev:client   # Vite on :5173 (proxies /api to :3000)