Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T01:55:22+00:00	DMARC	—	VALID	`e1c082cf0fe1…`
2026-08-17T01:55:22+00:00	SPF	—	VALID	`488b749bc76b…`