Record the rejected prototype shirt-shell experiment

TODO.md

@@ -234,13 +234,15 @@ owner reviews the silhouette and a production integration decision is recorded.
 - [x] Reject three cheap hem fixes: lowering the shirt to z 0.80 turns it into a unitard; tilting
       the hem up at the front reads as high-cut swimwear; a 13% hem flare reads as a peplum.
       The remaining V is the dark crotch hollow under a body-painted shirt, not a slot bug.
-- [ ] Owner reviews the updated MPFB body renders (`tmp/npc-parts/mpfb_proto/renders82/`).
+- [ ] Owner reviews the updated MPFB body renders (`tmp/npc-parts/mpfb_proto/renders84/`).
       Remaining known defects: the crotch hollow still reads as a V under the shirt hem, the
       shirt is only partly loosened by the 12% torso inflation, and the 2k-tri body budget leaves
       some angular thigh facets. A separate loose shirt shell is the proper fix for the first
       two; these are polish, not blockers for the body direction.
-- [ ] Build a separate loose shirt shell (open hem, shaped to the hips) instead of body-painted
-      cloth. It must fit in the 683 spare triangles or come with a head/body triangle rebalance.
+- [ ] Build a proper loose shirt shell instead of body-painted cloth. The quick open, flared
+      solidified tube (0.150→0.196 m, z 1.05→0.80, 24 segments, ~288 tris) read as a hanging
+      apron/tabard and was rejected. The shell needs a shaped torso, armholes and a curved hem,
+      not a tube. It must fit in the 683 spare triangles or come with a head/body rebalance.
 - [ ] Rebalance the triangle budget before rollout: 683 spare is below the ~1,200 the firefighter
       and hoodie variants need. Protect the head budget first; do not lower the accepted face.
 - [ ] Fix the low-budget seams before any rollout: weld the torso/hip/arm components after the