Record the two-builder distinction in MEMORY

MEMORY.md

@@ -81,6 +81,11 @@ canonical implemented-features list in `docs/development-status.md`.
 
 ## Gotchas / Known Issues
 
+- **Two character builders — do not confuse them.** `tools/blender_assets.py` is the real builder
+  for the **eight library characters, 18 gear pieces and props** (it has the 0.9.4 face/hand
+  sculpting in `_face()`/`_hands_and_shoes()`); `tools/npc_pipeline.py` builds **only**
+  `assets/models/generated/npc_base.glb`, the frozen plain-primitive fallback. Reading
+  `npc_pipeline.py` to judge the library's face/hand detail is wrong.
 - **Pose capture is blocked** (narrowed 2026-11-03): the recipe (SubViewport + `force_draw()` +
   `force_update_all_bone_transforms()` + disabled process/physics) still yields byte-identical rest
   frames. Decisive probe: teleporting the avatar renders (diff 10) but moving its `Rig` child does