Booking tax invoice / receipt

Runs booking.receiptDetails; owner-only. Returns the seller entity, the sequential invoice number and issue date once one has been issued, the stored card's last 4 digits, and the buyer's company name/tax ID — the invoice's own immutable snapshot once an invoice exists, or the booking's still-editable fields before that (#2229). Native clients build the invoice PDF client-side from this payload, the same way the web booking detail page does.