kirankbk/ShreSaiBusinessBackend ? reverse-engineered prompt

Build me the backend for a small business app called ShreSaiBusinessBackend.

I want a working Node based API server with a clean structure for auth, routes, controllers, middleware, and config. Set it up so I can register, log in, protect private endpoints, and handle errors in a simple reliable way. Please make the server start properly, wire the routes together, and keep the code organized so it’s easy to add more features later.

If anything is missing, make reasonable choices and look up current docs online if you need to. I’d also like basic setup for environment variables and anything needed so the project runs without extra guesswork.