Invoice + Stornorechnung/Gutschrift PDFs get a modern header-band layout,
a "bereits beglichen" badge for immediately-paid orders, labelled bank
details, and a per-tax-rate summary breakdown. Correction invoices can
now be re-downloaded from the account (regenerated deterministically,
not stored as files, same approach as the original invoice). Return
requests capture a reason. Products can define bundles (bundleItems) and
a per-product VAT rate override, both snapshotted onto order items.
Invoice PDFs (§14 UStG line items, tenant-configurable VAT rate) are now
generated at checkout and attached to the confirmation email, plus
available on demand from the order-detail page. Payload-side, orders now
also email the customer on shipped/cancelled/return_requested/returned,
with Stornorechnung/Gutschrift correction PDFs attached for the latter two
so the original invoice's immutable number stays honest.
Marco