Diagnose a running scene

threejs-model-inspect checks the file; this checks the app. The doctor captures the app's renderer, scenes and animation mixers through three.js's official __THREE_DEVTOOLS__ hook, so it needs no changes to the app and works with React Three Fiber.

Paths: <this-skill-dir> is the directory containing this SKILL.md; replace it with that absolute path. The script needs Node 22+, a Chrome-family browser, and threejs-model-inspect installed next to this skill.