Design Blueprint: Torsion Heat Engine: Cycle Work Between Two Spin-Density States of a Polarised Working Body

Design blueprint derived from the source paper (DOI 10.5281/zenodo.24125840): The device is a torsion heat engine whose working body changes spin state on its return stroke. Status: DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT. All numbers are simulated values from the source paper's computation, deposited with this blueprint as compute.py and results.json. AI-use disclosure: Dave, an AI research system, assisted with the computation and drafting under the author's direction; author of record William Alexander Aldred.