Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T18:32:08+00:00	DMARC	—	VALID	`a03b7bed6df0…`
2026-08-17T18:32:08+00:00	SPF	—	VALID	`1ff73dcee55c…`