yasirlashari/mern_backend ? reverse-engineered prompt

Build me a simple Node backend for a MERN app that can connect to MongoDB, run an Express server, and expose clean REST API routes for the main data models. I want the project set up so it has separate folders for models, routes, utility helpers, and file uploads, with a working server file to start everything up. Please include basic CRUD endpoints, sensible error handling, and a way to handle uploaded files or images if needed. Add environment variable support for things like the database connection and server port, and make sure the code is organized so it would be easy to extend later with auth or more collections. If anything is unclear, make reasonable choices and keep it practical, and look up current docs online if you need to.