Guard gear fit with headless and Blender regression checks

The Python fit test now caps the glasses at 0.70x head width and requires a
positive bag clearance on both the coat and dress. The Godot character suite
loads head/back gear on six roles and checks attach parents, head width and
brow bounds, and that back gear reaches beyond the 0.26 m body silhouette.
Rebuilt and re-baked all 18 gear assets; no-op GLB export churn was reverted.
Headless 229/229, Python 87/87.

docs/blender-assets.md

@@ -41,7 +41,7 @@ flatpak run org.blender.Blender --background \
   --python "$PWD/tools/blender_assets.py" -- render
 python3 tools/blender_assets.py sheet   # -> docs/blender_previews/sheet_<category>.jpg
 python3 tools/blender_assets.py audit   # stdlib only; exit 1 on any issue
-python3 tools/blender_assets.py fit     # head/clothing fit, per character
+python3 tools/blender_assets.py fit     # head/clothing fit + bag-body clearance, per character
 python3 tools/blender_assets.py list
 godot --headless --path . --import      # after any rebuild
 ```