urmibehera359/mern-store-billing ? reverse-engineered prompt

Build me a simple store billing app for a small shop.

I want a full stack web app where I can add products, create bills for customers, keep track of totals, and see a basic history of past sales. It should have a clean frontend and a backend that saves the data properly, so I can come back later and still see everything. Make it easy to search products, add items to a bill, edit quantities, and calculate the final amount automatically.

Please include a simple, practical layout that feels usable for someone running a shop every day. If you need to check current best practices or docs while building it, go ahead and look them up online. Keep it straightforward and make sure the app runs well from the frontend and backend in this repo.