Breakthrough/PySceneDetect ? reverse-engineered prompt

Build me a Python tool and library that can analyze a video and find scene changes and cuts, then let me use those results in a simple command line app and from Python code.

I want it to detect fast cuts, fades, and more gradual transitions, then optionally split the video into separate scene files or save a few images from each scene. It should work with common video files, use ffmpeg when available for splitting, and be easy to run with a single command or a short script. Please include a clean default setup, a way to tweak detection sensitivity, and a config file for repeated use.

If it makes sense, add good docs, examples, and tests so it feels solid and easy to understand. Look up the current docs online if you need to, and match the behavior of a real scene detection tool rather than inventing a new workflow.