Cap counted per return case, not per line.
Floor counted per return case. 0 means photos are optional.
Photos upload only after the return exists, so the API cannot refuse to
create a case that is short of the floor. Enforce it in the form: block
submit until the customer has picked this many photos. Only applies to
case types that accept photos at all — with claimsOnly, an ordinary
return has no file picker and no requirement.
When true, only claims accept photos.