Record the rejected prototype shirt-shell experiment

MEMORY.md

@@ -48,11 +48,13 @@ canonical implemented-features list in `docs/development-status.md`.
   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,
+  were all rejected; the remaining crotch V is the dark hollow under a body-painted shirt. A quick
+  open, flared solidified tube (0.150→0.196 m, z 1.05→0.80, 24 segments, ~288 tris) also failed:
+  it read as a hanging apron/tabard. The real fix is a shaped shirt shell with armholes and a
+  curved hem, not a tube. 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`.
+  `tmp/npc-parts/mpfb_proto/renders84/`; 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