Fixed
- Cancelling from the documents overview works again. Clicking "Cancel" in an invoice's card menu used to show an error message instead of doing anything. Now it automatically creates and opens a credit note draft — the invoice is considered cancelled once you issue and send that credit note.
- No more accidental cancellations without a credit note. In one place, issued invoices could still be cancelled or archived directly without creating a credit note. This is now consistently prevented — cancellations always go through a credit note.