Equipment rental

An owner lists a machine under canonical cre8.rental.v1 terms, hashed onto the unit. A check-out reserves the estimate plus a deposit that shrinks with the renter's rental reputation and schedules the return. The check-in bills the readings against the terms the rental went out under, settles the hold to the owner, refunds the rest, mints the machine's use (cre8/equipment/{class}/{measure}), and mints rep for a clean return or slashes it per day late. Rent earns credit toward a purchase option.