Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-18T13:47:03+00:00	DMARC	—	UNKNOWN	`b49656369da5…`
2026-08-18T13:47:03+00:00	SPF	—	VALID	`0dfb80bce2a4…`