kumark79-tech/invoice-builder ? reverse-engineered prompt

Build me a desktop app for making invoices and quotes for freelancers and small businesses.

It should work offline, keep all data on the user’s machine, and let them either use a local database file or connect to PostgreSQL if they want. I want a simple place to manage businesses, clients, items, taxes, discounts, currencies, and payment info, then create invoices and quotes from that data. Documents should be easy to edit, searchable, and saved with proper status tracking like unpaid, partially paid, paid, or closed.

Please add clean PDF export with a live preview, support for logos, signatures, watermarks, custom colors and fonts, and options for A4 or Letter. It would be great if users can back up and restore everything, import and export data, and generate invoice XML for European e invoicing standards. Make it feel polished, easy to use, and ready for Windows, Mac, and Linux. If you need current docs for any libraries or formats, look them up online.