Invoices are the official accounting document for every order — they ensure that the business case has a written form that can be presented to an accountant, tax office, or auditor. The `/invoice` module therefore serves as a complete archive and workspace for all tax documents of the organization: invoices can be viewed, downloaded, corrected, notes can be added, and they can be mass exported for monthly closing. Because the module is closely integrated with orders, bank transactions, and payment gateways, most invoices are issued, matched with payments, and closed entirely automatically, so human intervention is involved...
