Prototype evidence

This page orients. The canonical contract agents load is skills/chart-work/references/prototypes.md.

A prototype exists to settle a decision.

Build the smallest comparison that makes the contested behavior observable. Record the question, stable artifact, how it was exercised, the observation, the developer's decision and rationale, and open uncertainty.

Keep observed behavior separate from judgment. Keep the artifact inspectable while the decision depends on it. Frontend prototypes also follow Frontend mockups.