yuvrajsinghsoni07-ui/MernAssignments ? reverse-engineered prompt

Build me a simple backend project in JavaScript that shows these MERN assignment topics in a clean way.

I want separate sections for Mongoose schema setup, Joi request validation, a service layer, a basic CRUD API, solid error handling, and JWT based login and protected routes. Keep it easy to understand and organized so I can use it as practice or a class assignment. Use a MongoDB app with a few example resources, and make sure the routes can create, read, update, and delete data, with validation and helpful error messages when something goes wrong.

Please wire everything together so it feels like one complete app, not just random examples. If you need current library details, look up the latest docs online. Also make the code readable and include whatever setup is needed so I can run it locally and test the endpoints quickly.