Record current MPFB body prototype measurement and neck review

TODO.md

@@ -203,18 +203,24 @@ owner reviews the silhouette and a production integration decision is recorded.
       apply the helper MASK, scale to 1.81 m, retarget the A-pose arms to the contract wrist
       (`x=±0.27`, `z=0.78`), cut the neck at 1.505, decimate, bisect the clothing boundaries, paint
       the five slots, add a short neck flare, project hands, rounded shoe shells, cuffs, the
-      accepted head and the 14-bone armature. Current output: **15,917 tris / 9,543 raw verts /
-      1.811 m / 14 bones / 10 materials**; `inspect` clean, feet grounded.
+      accepted head and the 14-bone armature. Current output: **15,333 tris / 9,241 raw verts /
+      13,314 seam-split verts / 1.810 m / 14 bones / 10 materials**; `inspect` clean, feet grounded.
 - [x] Replace the spiky decimated MPFB hands with the project palm/finger primitives, straighten the
       splayed MPFB feet so the shoes point forward, and use rounded shoe shells + cuffs instead of
       flat blocks. Use flat slot colours in the prototype because the one-shot MPFB UV unwrap does
       not match the per-slot NPC atlases.
-- [ ] Owner reviews the MPFB body renders (`tmp/npc-parts/mpfb_proto/renders/`): neck reads as a
-      short collar, boxy/finned outer thighs at the 2k body budget, blocky shoe silhouette, and
-      seam gaps that grow when the body target is raised above ~2k tris.
+- [ ] Owner reviews the current MPFB body renders (`tmp/npc-parts/mpfb_proto/renders55/`):
+      the head/hair read well, but the decimated neck stub is boxy where the accepted head sits on
+      it, the shoes are still block-shaped, the ankles are pencil-thin where they meet the shoe
+      shells, and the shirt hem forms a V at the crotch. Earlier collar/neck-blend attempts were
+      rejected (disk shelf, neck brace, sawtooth collar); the current build ships no collar.
+- [ ] Fix the neck junction before any rollout: either cap and taper the accepted head's open
+      bottom in `makehuman_head.glb` (rebuild the source, re-review the face) or insert a welded,
+      smooth neck mass with enough poly budget to avoid the decimated square prism. Do not hide it
+      with a torus/flat disk collar; both read as a brace or shelf.
 - [ ] Fix the low-budget seams before any rollout: weld the torso/hip/arm components after the
       bisects, protect the hip/knee loops during decimation (or rebalance head/body triangles), and
-      rebuild the neckline so the accepted head does not sit on a flared collar.
+      rebuild the shoes/ankles so the leg does not taper to a point above a block.
 - [ ] Record the production integration decision: either bake the approved MPFB body to a committed
       source GLB (CI and fresh checkouts stay MPFB-free) or keep the procedural body as the shipped
       path. Do not add the MPFB extension as a build/CI dependency.