dsh-cad-design: A Parametric CAD Tool for DSH

`dsh-cad-design` is a parametric CAD plugin designed for DeepSeek Harness, integrating CadQuery and ezdxf to give agents mechanical design capabilities. It covers the complete workflow of 3D modeling, 2D drafting, geometry validation, preview rendering, and exporting formats such as STEP/DXF. Installation requires specifying a profile and configuring dependencies, after which agents can automatically load skills, iterate on designs by writing code, and ultimately output manufacturing files. This tool fills the gap in agent-based engineering geometry processing and is suitable for automated mechanical design workflows.