joandson19/APPFATURAS_PWA_PROVEDOR ? reverse-engineered prompt

Build me a simple PWA called FaturaFacil for a telecom provider, where customers can log in with CPF or CNPJ and stay signed in if they want.

I want the app to show open and overdue bills, recent paid bills with a receipt link, and let the customer generate Pix payment details with a QR code and copy and paste text. It should also show temporary signal unlock if that is available, and pop up maintenance alerts pulled from the provider system.

Please make it work as an installable app on mobile, with push notifications for bills and important notices. The app should connect to an existing SGP API, use a hidden config file for the server settings, and include a secure webhook endpoint so messages can be sent to one customer or to everyone. If needed, look up current docs online to make sure the service worker and push setup are done the right way.