Dependency-free PNG codec, perceptual metrics (structure / color / detail /
bands), side-by-side + heatmap + per-region crops, a measured spec from the
approved comp (grid overlay, sampled palette, plate list), and a phase state
machine whose spec / plates / hero gates run the diff instead of asking the
model to remember the image.
AI-assisted (Claude).
Co-Authored-By: Claude <noreply@anthropic.com>
