Load and animate the Blender-authored NPC base mesh

Wire the skinned model from ADR-0013 into NpcAvatar:

- _build_skinned_body() instantiates the imported npc_base.glb, binds the 14
  armature bones, and keeps the procedural _build_body() as the offline
  fallback (use_skinned_model can force it in tests)
- outfit_for()/layer_for() tint the five material slots through the new
  SurfaceMaterials.npc_slot(); accessories and hand items attach under Rig/Head
- the existing limb pivots (Hip/Knee/Shoulder/Elbow/Hand + Head marker) keep the
  old animation math; _sync_skeleton() copies their rotations to bones. Bone
  pose rotation is absolute local orientation, so it is composed with the rest
  basis (otherwise the whole body snaps into a broken pose)
- skinned rigs scale uniformly (non-uniform parent scale shears the skin) and
  keep Rig/Head for the focus cone, nametag, and reaction tag
- commit the editable npc_base.blend plus a .gdignore: Godot's editor otherwise
  tries to import the blend and hangs during --import
- npc_pipeline audit tests (contract, textures, clean GLB, committed source)

Verification: headless 212/212, Python tooling 60/60, NPC budget 16 avatars =
144 meshes at ~6.9 ms, movement/focus/props smokes pass, compare 11 good / 0 bad.
TODO Phases 0-3 checked; environment lift and release remain.

MEMORY.md

@@ -20,6 +20,18 @@ Session memory for durable decisions, state, and gotchas. Keep concise, remove o
 - Shift length is the scenario's `shift_duration_s` (900 s in all three venues). Tests and the screenshot tool override elapsed time; they do not change the default.
 - RNG: NPC reactions and event scheduling are seedable for deterministic tests.
 
+- **Blender invocation (v0.6.0):** `flatpak run org.blender.Blender --background --python
+  /run/media/system/DATA/Documents/06-games/security-game/tools/npc_pipeline.py -- build`.
+  The flatpak cannot read `/tmp`; use absolute repo paths. `assets/models/npc/.gdignore` is
+  required, otherwise Godot's editor tries to import the committed `.blend` and hangs during
+  `--import` (also add `.gdignore` to local build/squashfs folders when scanning is slow).
+- **Skinned NPC integration (v0.6.0):** `NpcAvatar._build_skinned_body()` loads
+  `npc_base.glb` and keeps `_build_body()` as fallback (`use_skinned_model=false` in tests).
+  Bone pose rotation is the **absolute local orientation**, not an offset from rest: compose with
+  `get_bone_rest(i).basis` or the whole body snaps to a broken pose. Proxies named Hip/Knee/
+  Shoulder/Elbow/Hand + Head marker preserve the old animation math; `Rig/Head` is the marker.
+  Five material slots are tinted via `SurfaceMaterials.npc_slot()`; keep `_rig.scale` uniform on
+  the skinned path. Budget: 16 avatars = **144 meshes**, ~6.9 ms headless.
 - **NPC facing (fixed after v0.5.0):** the avatar's visual front is **+Z** (procedural eyes
   and the Blender model's face). Godot `look_at()` aims **-Z**, which made every NPC walk
   backwards. Use `NpcAvatar.yaw_towards(dir)` and set `rotation.y`; do not call `look_at()` on