Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T20:07:47+00:00	DMARC	—	VALID	`6f85e1c157b7…`
2026-08-21T20:07:47+00:00	SPF	—	VALID	`ec46697276ec…`