Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T02:26:05+00:00	DMARC	—	VALID	`d6c42c7ef72f…`
2026-08-17T02:26:05+00:00	SPF	—	UNKNOWN	`5748df1e4bc3…`