Add head subdivision variants and pick s48 after 1.5m/1.85m comparison

docs/3d-model-review.md

@@ -232,6 +232,20 @@ brow −0.150, chin −0.149, jaw step −0.11, forehead −0.126→−0.078. Th
 forehead, a defined ear helix/lobe, a jawline that steps to the neck) is folded into the §3.2
 variant comparison; the neck is part of `_skin_body`, so the standalone head always lacks it.
 
+### Head subdivision comparison (2026-11-04)
+
+Three `head_proto` variants at UV-sphere segments 24/48/64 were rendered at 1.85 m and 1.5 m in
+front/three-quarter/profile and judged side by side:
+
+| Variant | Verts / tris | 1.85 m | 1.5 m | Verdict |
+| --- | ---: | --- | --- | --- |
+| s24 | 670 / 1,168 | lumpy, nose/lips melt into the chin | jagged silhouette, no mouth | reject |
+| s48 | 1,558 / 2,944 | eyes/brows/nose/lips read cleanly | features resolve cleanly | **pick** |
+| s64 | 2,470 / 4,768 | visually identical to s48 | indistinguishable from s48 | reject (wasted verts) |
+
+The chosen s48 is the `head_proto` default; the rejected s24/s64 stay local under
+`tmp/npc-parts/`.
+
 ## Scorecard skeleton
 
 Verdicts use `qa-review` semantics: **P0** (blocker: wrong scale, broken normals, budget fail),