Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T22:44:01+00:00	DMARC	—	VALID	`f0709b2f2d59…`
2026-08-21T22:44:01+00:00	SPF	—	VALID	`027f9e9379c1…`