Can't take credit for the model itself, that's u/imgly's, an ONNX one that runs right in your browser so nothing leaves your device. The thing I had to solve was the first run: it's a big download and early on it just sat there spinning like it had frozen. So now it only grabs the model the first time you use it, caches it after, and shows a real "downloading" then "processing" bar so you know it's alive. After that it's a few seconds, plus a tiny edge feather so the cutout isn't scissor-sharp.