Close and archive the 0.9.9 milestone, record that the upstream clips stay unused, and harden the fallback test

MEMORY.md

@@ -87,8 +87,11 @@ canonical implemented-features list in `docs/development-status.md`.
   lost forearms, stretched shins). The owner chose to **adopt the Quaternius 62-joint rig at
   runtime** instead of warping: `NpcAvatar` maps the Quaternius joint names, gear attach points
   are re-derived from the Quaternius skeleton (hip ≈0.87, shoulder ≈0.148/1.39, wrist ≈0.99,
-  knee ≈0.52), the mesh keeps source LOD (arm-down rest pose baked), and Idle/Walk play directly
-  on the 62-joint rig (no retarget).
+  knee ≈0.52) and the mesh keeps source LOD (arm-down rest pose baked). **The 24 upstream clips are
+  not played**: `_animate()` drives the proxies and `_sync_skeleton()` writes the bone poses, which
+  is what the FSM already needed for sitting, hand-raising and head turns. Playing the clips would
+  replace that state machine, not supplement it, so all 24 stay unused and the clips are authoring
+  reference only.
 - **Engine baseline:** Godot 4.7.2 stable (official editor `~/.local/bin/godot`). The system's
   `godot-runner` cannot load arbitrary project paths (compiled without path overrides); use the
   official editor binary.