mohamedelareeg/POS — reverse-engineered prompt

Build me a Windows desktop Point of Sale app for a small retail shop. I want to open it in Visual Studio, run it locally with a SQLite database, and log in with an admin account or a normal user account.

The app should have a clean modern WPF interface with a sign in page, dashboard, sales screen, inventory screen, users screen, roles and permissions screen, and reports. It should let staff create sales and invoices, handle returns, scan or enter barcodes, manage products and stock, record purchases, track customers, suppliers, debts, installments, treasury money in and out, and expenses.

Admins should be able to control which menu items each role can see or use. Regular users should only see the parts they have permission for. Add simple charts for sales or business overview, backup settings, company settings, and default test users so I can try it right away.

Keep the code organized and maintainable. Look up current docs online if you need to.