freesewing/pattern-via-io — reverse-engineered prompt

Build me a small Node based example that lets me use FreeSewing as a simple pipe. I’ve got measurement and option settings as JSON, possibly coming from a Python app, and I just want to send that JSON into stdin and get a finished pattern SVG back on stdout. Include a sample settings file and make it easy to run from the command line so I can do something like piping the file into the script and saving the SVG output.

I also want a second script that reads the same JSON input but prints useful pattern data as JSON instead of an SVG, mainly the rendered parts with their points and paths, so I can inspect or reuse that programmatically.

Use one of the standard example designs that FreeSewing supports, and make it easy to swap to another design later if I want. Add a short README with the exact commands to install and run it. If anything is unclear, look up the current FreeSewing docs online.