Opening a case copies what must not move afterwards — the session count and the
list of body areas, each with its category name — because a treatment record is
a medical document and editing settings tomorrow must not rewrite what was done
yesterday. The areas are the leaf categories under the service's own category:
"توتال" contains bikini, leg and hand, and treatment happens on those three, not
on the grouping node above them. A category with no children is its own single
area, so "لیزر دست" gets one area rather than none.
Every session in the course is created up front so that "session 5 of 8" has
somewhere to live, but none of them is booked: creating eight real appointments
would lock eight months of slots for a patient who may not attend session three.
CategoryClosureResolver gains leaves(); the graph walk it already does is what
tells a leaf from a grouping node, so this belongs next to descendants() rather
than in a second traversal elsewhere.
TreatmentCase and TreatmentSession carry no money field, and must not: billing
lives on PatientSession, which is created when an appointment is confirmed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
