OptionalgovernsOrgan → vital coupling. A VitalSign key (see lib/vitals/Vitals.ts);
typed string here deliberately to keep BodyPlan free of any
import from lib/vitals.
OptionalinnervatedCanonical dotted path, e.g. 'body.arm.left.hand'.
Tree edge to the parent part, or null for the root.
OptionalseverableCan detach — future part-promotion seam.
OptionalsuppliedNamed tissues + masses — NOT a single default material.
Typed anatomical part descriptor — the model layer, declared ONCE on the shared BodyPlan flyweight (not per-instance). Instances carry only deltas (
VitalsMixin.bodyPartDeltas); the anatomy resolver merges instance-delta → BodyPlan-structure (thegetMaterial/getSpeciesresolution shape).Stable dotted
body.*keys are the identity anchor everything downstream points at: traumasite, the slot/vital couplings, and (deferred-with-seam) the innervation / vascular graph and part-as-Stuff promotion.