Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T06:02:31+00:00	DMARC	—	VALID	`1796abbd3f5c…`
2026-08-21T06:02:31+00:00	SPF	—	VALID	`d5c01b1e96c9…`