Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-16T21:32:02+00:00	DMARC	—	VALID	`a7905b01068e…`
2026-08-16T21:32:02+00:00	SPF	—	VALID	`0d4327f6d2e3…`