chore: ignore bought and third-party assets [skip ci]

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01As1S7fpDqEDnZxcGbSSoUW

.gitignore

@@ -44,3 +44,17 @@
 /Model
 __pycache__/
 *.lnk
+
+# bought / third-party models, animations, textures and voice clips - never commit (stripped from history 2026-10-24)
+VRoid/
+AnimBackup/
+Assets/
+Sounds/
+scratch/
+*.vrm
+*.vrma
+*.glb
+*.fbx
+*.wav
+*.pmx
+*.psd