Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T00:15:14+00:00	DMARC	—	VALID	`c4938bad9048…`
2026-08-17T00:15:14+00:00	SPF	—	VALID	`b8212d2f2f08…`