Add MakeHuman head hair/body prototype and 12-variant rollout plan

TODO.md

@@ -26,10 +26,12 @@ five tint slots, 16,000/16,000 character cap, optional extra bones beyond the re
 **Current state:** `assets/models/npc/` contains the tracked frozen `npc_base.blend` and its
 gitignored `.blend1`; the 12 production characters are assembled procedurally by
 `tools/blender_assets.py` from `_shape_head_mesh`, `_face`, `_hair` and `_hands_and_shoes`.
-There is no per-part source asset library yet. The MakeHuman body prototype and its temporary
-head/hand swap live under `tmp/npc-research/` and are not the shipped path. This overhaul supplies
-the reusable head/face and hand parts that both the procedural characters and the MakeHuman body
-can consume.
+The MakeHuman head is now a second head source (`build_character(head="mh")`,
+`build --head mh`, `npc_parts.py assemble --head mh`) and all 12 variants assemble inside the
+16,000-triangle cap with it. The procedural body, hands and clothing remain unchanged. The
+MakeHuman body prototype and its temporary head/hand swap live under `tmp/npc-research/` and are
+not the shipped path. This overhaul supplies the reusable head/face and hand parts that both the
+procedural characters and the MakeHuman body can consume.
 
 This workstream supersedes the face/head and hands items in §C until the prototypes are approved;
 the rest of §C remains the broad review checklist.
@@ -93,16 +95,18 @@ the rest of §C remains the broad review checklist.
 - [x] Compare two or three subdivision/loop variants at 1.85 m front/three-quarter/profile and a
       1.5 m portrait. Pick the variant that reads best before changing all 12 characters; keep the
       rejected variants local.
-- [-] Rebuild a standalone MakeHuman-derived head from the researched CC0 base and save it to
+- [x] Rebuild a standalone MakeHuman-derived head from the researched CC0 base and save it to
       `assets/models/blender_src/makehuman_head.glb`; record provenance/review in
-      `docs/makehuman-head-review.md` and the preview sheet. (Final build: 12,641 tris / 7,690
-      split verts; assembled `npc_casual` 15,532 tris / 13,310 verts / 14 bones, `inspect` clean.
-      Latest attempt: skin eyelid mask, recessed globes, flat iris/pupil discs, surface-anchored
-      brows. Vision verdict: still **REJECT** — globe depth is inconsistent between front,
-      three-quarter and profile, the lid does not visibly clip the globe, and the iris reads
-      decal-locked at three-quarter; prototype stays local and un-integrated.)
+      `docs/makehuman-head-review.md` and the preview sheet. Final build: 12,642 tris /
+      7,690 split verts, bounds x −0.094..0.094, y −0.180..0.042, z 1.530..1.803. The owner
+      accepted the **basic human head** on 2026-11-04; the automated vision gate still records
+      the eye-region REJECT as deferred polish (globe depth, lid overlap, iris at three-quarter).
+      The assembled path now adds a skull-conforming hair cap, a hidden-scalp trim and a narrowed
+      neck/shoulder body. Assembled `npc_casual --head mh`: 14,753 tris / 12,822 raw / 12,823
+      seam-split verts / 14 bones / 9 materials, `inspect` clean.
 - [ ] Build true upper/lower eyelid masses that overlap the globe in front, three-quarter and
-      profile views (not a socket hole), then re-run the vision gate before integrating the head.
+      profile views (not a socket hole), then re-run the vision gate. Deferred: the owner accepted
+      the basic head, so this is polish, not a rollout blocker.
 
       Compared `head_proto` at seg 24 (670 verts), 48 (1,558 verts) and 64 (2,470 verts) at 1.85 m
       and 1.5 m, front/three-quarter/profile. Vision-judged: **s48 wins** — s24 is too faceted
@@ -117,12 +121,11 @@ the rest of §C remains the broad review checklist.
       imported GLB came out black and is superseded by the proper `.blend`-source bake). Flag: the
       prototype ears reach x ±0.162 vs the 0.1575 head-radius reference, so headgear may clip and
       must be re-measured at rollout.
-- [ ] Get owner sign-off on the one-variant prototype, then roll the approved head/face into the
-      other 11 variants one asset family at a time, with a before/after sheet per batch.
-      **Blocked on owner sign-off.** Sign-off material is ready: the s48 prototype vs the current
-      `_face` at 1.85 m front/three-quarter/profile
-      (`docs/blender_previews/sheet_head_proto_before_after.jpg`); the s24/s48/s64 comparison table
-      is in `docs/3d-model-review.md`. Rollout waits for the owner's go/no-go.
+- [-] Owner review of the assembled one-variant prototype (`npc_casual --head mh`) before the
+      12 shipped GLBs change. The basic human head is accepted (2026-11-04); the review now covers
+      the skull-conforming hair cap and the narrowed neck/shoulder body silhouette. Local renders:
+      `tmp/npc-parts/prototype_mh/renders/` (portrait front/three-quarter/profile + full body).
+      Rollout starts only after this review.
 
 ### 4. Hands and grip prototype
 
@@ -151,6 +154,30 @@ the rest of §C remains the broad review checklist.
 
 ### 5. Assembly and rollout
 
+**MakeHuman 12-variant rollout.** - [x] Make the head source selectable from the main builder:
+      `blender_assets.py build --head mh --only npc_casual,...` and
+      `npc_parts.py assemble --variant <name> --head mh --out <stem>`. The default stays `face`
+      until the hair/body review passes.
+- [x] Verify every variant assembles with the MakeHuman head inside the 16,000/16,000 cap
+      (pre-export triangle counts, `inspect` clean; `npc_casual` seam-split verts 12,823):
+      `npc_casual 14,753`, `npc_jacket 15,153`, `npc_coat 15,817`, `npc_vest 15,579`,
+      `npc_dress 15,215`, `npc_hoodie 15,837`, `npc_firefighter 15,987`, `npc_guard 15,729`,
+      `npc_crowd_a 14,947`, `npc_crowd_b 14,693`, `npc_crowd_c 15,433`, `npc_crowd_d 15,833`.
+- [x] Recover head budget without touching the accepted face: remove head faces fully covered by
+      the hair cap, keep boundary faces as a safety band, and trim the hidden neck plug to 12
+      segments. This saves ~950 tris on every variant.
+- [ ] Owner approves the hair cap and full-body silhouette on the local `npc_casual` prototype.
+- [ ] Rebuild the 12 committed character GLBs with `--head mh`, in asset-family batches, then
+      regenerate their AO maps and manifest entries. Never run a no-op full-library rebuild.
+- [ ] Run `blender_assets.py audit`, `fit`, `inspect` and `texels`, plus
+      `python3 tools/npc_proportions.py report`; record the 12-variant proportion table.
+- [ ] Re-run the Godot NPC tests and capture the 12 × 6 baseline
+      (`src/test/capture_npc_baseline.gd` → `python3 tools/npc_baseline.py sheet`); inspect the
+      sheet for outliers before committing.
+- [ ] Update `docs/makehuman-head-review.md`, `docs/3d-model-review.md`,
+      `docs/blender_previews/README.md`, `docs/npc-model-sourcing.md`, `CREDITS.md` and
+      `docs/development-status.md` with the accepted head/hair/body state and final counts.
+
 - [ ] Integrate the approved parts into `build_character` with deterministic joins, weights, UVs and
       AO. The final output remains one `npc_base` skinned mesh under the existing 13-core armature;
       optional extra bones are allowed but the core rest positions stay fixed;