Ref T6881. This generates a product, purchase and invoice for users, and there's sort of some UI for them. Stuff it doesn't do yet:
- Try to autobill when we have a CC;
- actually tell the user they should pay it;
- ask the application for anything like "how much should we charge", or tell the application anything like "the user paid".
However, these work:
- You can technically pay the invoices.
- You can see the invoices you paid in the past.