monasr220/BookAThing ? reverse-engineered prompt

Build me a simple booking system for a final project.

I want a working backend in JavaScript that lets people create a booking, view existing bookings, update them, and cancel them. It should feel like a real reservation app, so include basic validation, clear error messages, and a simple way to avoid double booking the same time slot.

Keep it easy to run and test locally, and set it up in a clean, organized way so I can extend it later if needed. If you need to check current docs for anything, go ahead and look them up online.

Make sure the project is complete enough that someone can clone it and understand how to use it right away.