Cornerstone is a set of JavaScript libraries that can be used to build web-based medical imaging applications. It provides a framework to build radiology applications such as the OHIF Viewer.
Didn't have time and budget when we were developing segmentation tools to port that one, it should be similar to other scissors so I would be happy to review your code if you want to contribute
Why is the Correction Scissors Tool in Cornerstone Tools 4.0 not available in the tools for Cornerstone 3D beta