Bake the rest pose, warp to the contract, and record the failing silhouette gate

docs/npc-model-sourcing.md

@@ -170,6 +170,34 @@ Optional extras (allowed by the contract; kept if they survive within 24,000 ver
 Dropped (never shipped): `PT.L/R` (pole targets carry no deforming weights), and the
 `Root`/`Body`/collar-`Shoulder` collapse bones above.
 
+## Rest-pose and proportion-warp measurement (2026-11-05)
+
+The rest-pose bake (T-pose → arm-down) works: rotate the `UpperArm.L/R` pose bones −90° around
+their local X, apply the Armature modifier to bake the deformation, then `armature_apply` to bake
+it as the new rest pose (see `tmp/npc-research/warp_full.py`). The mesh deforms cleanly to the
+arm-down pose (deformed bounds x ±0.221 vs the T-pose ±0.811).
+
+The proportion warp to the contract positions is measured and it **distorts the silhouette**:
+
+| Joint | Quaternius | Contract | Delta |
+| --- | --- | --- | --- |
+| Hips height | 0.869 | 0.62 | −0.249 (lower hip) |
+| Head top | 1.614 | 1.82 | +0.206 (raise head) |
+| Shoulder x | 0.148 | 0.27 | +0.122 (widen) |
+| Arm (shoulder→wrist) | 0.402 | 0.60 | ×1.49 |
+| Arm (shoulder→hand tip) | 0.429 | 0.70 | ×1.63 |
+| Leg (hip→ankle) | 0.835 | 0.62 | ×0.74 |
+| Torso (hip→head) | 0.745 | 1.20 | ×1.61 |
+
+The vision judge reads the warped mesh as: paddle/claw hands (the 1.63× arm stretch blows the
+hand out), forearms lost into the torso, stretched shins, and "long legs + short torso". The arm
+must either stay short (a "shortened arm" vs the contract hand) or stretch 1.63× (a distorted
+deltoid + hand) — both are the gate's rejection conditions.
+
+**Finding:** the Stage 1 proportion warp cannot preserve the Quaternius silhouette at the
+contract proportions; the gate fails and Stage 2 (a 62-joint runtime ADR) is indicated. Do not
+start the 12-variant rebuild on the warped base.
+
 ## Contract mismatch
 
 The expensive part is the rig and proportions, not the mesh. The source has a