Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T09:24:03+00:00	DMARC	—	VALID	`6ca7c78a5311…`
2026-08-17T09:24:03+00:00	SPF	—	VALID	`cc0fd9733c4c…`