Add the connected-shell head prototype (head_proto) with sculpted sockets/nose/lips/ears

docs/3d-model-review.md

@@ -210,6 +210,19 @@ Part sources and preview GLBs live under `tmp/npc-parts/<variant>/` (gitignored
 committed. No new committed `.blend` source tree is added without a docs/ADR decision — the
 frozen `npc_base.blend` stays the only tracked `.blend`.
 
+### Head prototype (in progress 2026-11-04)
+
+`tools/npc_parts.py build --part head_proto` is the first connected-shell attempt: a seg-48
+head sphere is displaced (not floating spheres) into eye sockets with an orbital rim, a nose
+bridge/tip/ala, upper/lower lip volumes, and extruded ears with a concha recess; the eyeballs
+stay separate. Local renders live under `tmp/npc-parts/npc_casual/head_proto_*.png`.
+
+Vision-judged after two iterations: the nose and ear now protrude in profile (mesh y-min
+−0.186 vs the −0.155 shell front), but the cranium still reads as a "ball with a nose" — the
+face plane is not flattened, the jaw/chin does not taper, and the nose reads as a narrow spike.
+Next refinement before the 1.5 m/1.85 m comparison: flatten the face plane, taper the jaw/chin,
+widen the nose bridge, and shape the back of the skull.
+
 ## Scorecard skeleton
 
 Verdicts use `qa-review` semantics: **P0** (blocker: wrong scale, broken normals, budget fail),