Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-16T23:48:51+00:00	DMARC	—	VALID	`14b0dbf1e092…`
2026-08-16T23:48:51+00:00	SPF	—	VALID	`5deafe0ce84a…`