Capstone: Eval Operating System

Build the final boss in 18-capstone-eval-operating-system. It combines dataset versioning, rubric calibration, model-judge checks, offline regressions, canary rollout gates, trace-backed debugging, and refresh cadence. Small ask. Basically Tuesday, if Tuesday had governance.

• Versioned golden and stress sets with slice-level reporting.
• Human rubric calibration paired with model-judge disagreement review.
• Deterministic CI checks for high-risk regressions.
• Canary rollout thresholds tied to offline and online evidence.
• Trace metadata for failed examples, judge drift, and refresh decisions.
• A Good / Bad / Ugly launch memo reviewers can audit later.