How many of this port the body plan declares.
Sense-channel vocabulary — one of the five physical channels
declared by SenseChannel. The eyes-modality entry uses
'vision' (the channel/process word), not the legacy organ
word 'sight'; the substrate's vocabulary is unified across
BodyPlan / Detail / <sense> MML / SenseChannel TS type.
'frontal', 'lateral', 'dorsal', 'forward', 'circumferential'.
Anatomy descriptor for a sensory apparatus. Capability (range, acuity) does NOT belong here — that's species-side. Decomposes as three flat scalars under default hydration; if it grows nested fields a
SensoryPortMarshallerhandles serialization.