Running 8 parallel agents is exactly when silent deviations get expensive — one agent writes to the wrong path and exit code 0 hides it. K9 Audit drops into .claude/settings.json and records every tool call as a cryptographic evidence chain. When something breaks at 3am, k9log trace --last shows you the exact deviation across all sessions, not just which one crashed. https://github.com/liuhaotian2024-prog/K9Audit