The Postgres backend returned tamper_evidence=True as a constant while
docs/integrity.md permits the claim only when a live external chain-head
attestation exists. The one attestation on record is 2026-08-16 and no job
renews it, so audit-core was telling every sender it had a property whose
precondition was unverified — the §9.6 defect it twice corrected in
gate-house's doctrine, turned inward.
evaluate_tamper_evidence() derives the flag from the chain report and the
mounted attestation, distinguishing seven states. Absence, staleness,
mismatch, an undated or unreadable attestation, a chain break, and an
unwalkable chain all degrade the claim rather than leave it standing.
Unreadable is treated as absent on purpose: a malformed file must not hold
up a claim a missing file would drop.
The freshness window is 168h against an intended daily cadence — seven
cadences, so a handful of missed runs degrade the claim rather than a single
one flapping it. Window and cadence are one contract in docs/integrity.md.
Production /readyz will now report tamper_evidence: false until
AUDIT-WP-0009-T02 schedules attestation. The claim was already false; it now
says so.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0185wifnLzCxjEY2MT1XbK7L
Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 713962@bnt-lap001
Assistant-Session: 2718d99d-d3ff-478f-83a2-3a30f01a02fc
tegwick
2f7f475e85