royalsuthan06/sparkbill2.0 ? reverse-engineered prompt

Build me a simple point of sale app for a crackers shop called SparkBill POS. I want it to work as a desktop window and also in a normal browser, with a clean offline friendly interface.

It should let me quickly search products by SKU or name, add items to a cart, change quantities, remove rows, and complete a sale with keyboard shortcuts for fast billing. I also need inventory management so I can add, edit, delete, and filter products by category or price. Please include sales reports with date filters like today, yesterday, last 7 days, and custom range, plus a way to open sale details and reprint invoices.

Use a local database that creates itself on first run, seed it with sample products, and generate PDF invoices automatically after checkout. Keep everything self contained with local assets, basic validation for phone numbers and payment, and make sure it starts easily with a simple run script. If you need current docs for any library, look them up online.