Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T10:13:33+00:00	DMARC	—	VALID	`cd7ee2a7f3d7…`
2026-08-21T10:13:33+00:00	SPF	—	VALID	`876c427fe12b…`