A single listing booking within a multi-listing attendee creation
Booking duration in days (defaults to 1 for 1-day bookings). Only meaningful when date is set.
Shared per-order token written on every row of one checkout (defaults to "" — legacy/parent-less bookings). Set once per create, not per caller.
The parent listing this row was folded under when it is a chosen child (defaults to 0 — not a folded child).