livealvi/.NET-Point-of-Sale-POS--Csharp ? reverse-engineered prompt

Build me a Windows desktop point of sale app for a small shop that can handle login and three roles, admin, cashier, and salesman.

I want the app to let the admin manage employees, products, stock, vendors, brands, categories, expenses, and salary history, plus do sales, generate bills, view sales history, and back up or restore the database. Cashiers should be able to make sales, print bills, view sales history, and manage stock. Salesmen only need to make sales and generate bills.

Please make it work as a classic desktop app with a clean form based interface, connected to a SQL Server database, and organized in a layered way so the code is easy to maintain. If you need to look up any current docs or UI details while building it, go ahead. Also include a simple dashboard and make the app feel ready for a real shop workflow.