Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-18T04:52:26+00:00	DMARC	—	VALID	`1b661a834c67…`
2026-08-18T04:52:26+00:00	SPF	—	VALID	`cc9e4f135f69…`