sgiammori/MERNStackBackend ? reverse-engineered prompt

Build me a clean backend for a MERN app in JavaScript.

I want a Node server that connects to MongoDB, has a simple project structure with models, routes, middleware, and config, and serves the app from a single entry point. Set it up so I can easily add API routes later, keep the code organized, and include a few basic examples of how the pieces fit together.

Please make sure it runs smoothly from the command line, uses environment variables for anything sensitive, and includes a public folder for any static files that need to be served. If you need to check current docs for the best way to wire things up, go ahead and look them up online.

Keep it practical and minimal, but make it solid enough that I can start building features on top of it right away.