Fix the prototype crotch material and loosen the shirt

MEMORY.md

@@ -33,9 +33,9 @@ canonical implemented-features list in `docs/development-status.md`.
   points/weights, removes the rig, applies the helper MASK, scales to 1.81 m, retargets the A-pose
   arms to the contract wrist, cuts the neck at 1.505, decimates, bisects the clothing boundaries,
   paints the five slots, adds a short neck flare, project hands, rounded shoes and cuffs, the
-  accepted head and the 14-bone contract armature. Current output: **15,317 tris / 13,507 glTF
-  verts / 13,513 seam-split verts / 1.810 m / 14 bones / 10 materials**; `inspect` clean and feet
-  grounded. The torso is inflated radially by 8% between z 0.84 and 1.40 to loosen the shirt. The
+  accepted head and the 14-bone contract armature. Current output: **15,317 tris / 13,690 glTF
+  verts / 13,702 seam-split verts / 1.810 m / 14 bones / 10 materials**; `inspect` clean and feet
+  grounded. The torso is inflated radially by 12% through z 0.72–1.40 to loosen the shirt. The
   neck is a radial cut of the decimated column bridged by a four-ring, 20-segment lathe (lower
   rings painted cloth, reads as a crew neck); the ankles are hidden by a bevelled 0.11 m shoe
   shell, an inset 0.111 × 0.286 m sole, a tongue and a 0.08 m pant cuff. Sleeve cuffs use the
@@ -45,10 +45,14 @@ canonical implemented-features list in `docs/development-status.md`.
   brace, shelf or donut, and vertex smoothing tore the open collar boundary into a dark hole. An
   untucked shirt-hem band at the hips also failed: it read as a hanging white flap at the crotch.
   Protruding flat sole plates read as skates/bricks and were replaced by an inset sole under a
-  rounded shell; laces were dropped for triangle budget. Remaining polish: V-shaped shirt hem at
-  the crotch, partly loosened shirt, angular thigh facets; a proper shirt shell is the fix. The
-  prototype uses flat slot colours because the one-shot MPFB UV unwrap does not match the per-slot
-  NPC atlases. Renders: `tmp/npc-parts/mpfb_proto/renders74/`; body-only: `body_only.glb`.
+  rounded shell; laces were dropped for triangle budget. The neck skin rule needed a `z > 1.35`
+  guard: without it the `radius < 0.08` test painted skin at the crotch. Lowering the hem to
+  z 0.80 (unitard), tilting it up at the front (high-cut swimwear) and a 13% hem flare (peplum)
+  were all rejected; the remaining crotch V is the dark hollow under a body-painted shirt, and a
+  separate loose shirt shell is the real fix. Remaining polish: crotch V, partly loosened shirt,
+  angular thigh facets. The prototype uses flat slot colours because the one-shot MPFB UV unwrap
+  does not match the per-slot NPC atlases. Renders:
+  `tmp/npc-parts/mpfb_proto/renders82/`; body-only: `body_only.glb`.
 - **Project agent skills (2026-11-03):** two tracked skills live in `.agents/skills/`:
   `gig-line-blender-asset-contract` and `gig-line-release-qa`. They are guidance only,
   add no runtime dependency and are referenced from `tools/README.md`. The third-party