kisxo/kyren-store-backend ? reverse-engineered prompt

Build out this shop backend so it can actually run and support a small online store.

I want a clean API for things like products, users, and orders, with the usual create, read, update, and delete flows where it makes sense. Make sure the routes, controllers, models, middlewares, and helper code all work together, and wire everything up from the main server file so I can start it and test it right away. If there is anything unclear, check the existing docs and the order.html file, and look up current docs online if you need to.

Please also make sure errors are handled nicely, request validation is in place, and the code is organized in a way that is easy to maintain. If there are any missing pieces or broken parts in the current project, fill them in so this feels like a usable backend for an e commerce store.