Restructured per ADR-0038 with Coverage-Statement-Block per Fault- Injection-Audit-Convention. Topology auto-populated. Pre-commit hook installed. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
3 mutations tested. 2 caught, 1 uncaught (M3: add unregistered-handle guard absent). Cheap-fill: added pcall assertions for add(unregistered) and toggle(unregistered).