Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T09:10:15+00:00	DMARC	—	VALID	`db7f913a9f3c…`
2026-08-21T09:10:15+00:00	SPF	—	VALID	`08e544cf335d…`