Unit: the mfa_pending BITE (db-injected so removing the rejection goes red), lockout, replay,
recovery-hash, decrypt-null graceful. Integration: enrollment, login->mfa_required, route-level
bite, recovery single-use, API-token bypass, verify lockout. Key-rotation: enroll under key A,
reboot under key B -> recovery still works, TOTP fails cleanly (no 500).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>