I gave it a shot, but got no luck getting animation data from a GLTF file. So, while I figure that out, how about switching to something simpler like MD5? ...and guess what? It's working!
I'm thinking about getting OBS installed and recording a tutorial video for actually building this and then starting to customize it, but here's a simple repo with readme instructions that gets you yesterday's screenshot.
Requires Windows, tested on Visual Studio 2022. 4 steps to have an #imgui sdl2 window ready to start hacking on. stb and box2d thrown in for good measure.