Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T04:22:37+00:00	DMARC	—	VALID	`0d5bf38195cc…`
2026-08-17T04:22:37+00:00	SPF	—	VALID	`d5f83fe0e314…`