Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-18T05:54:09+00:00	DMARC	—	VALID	`bcc25ade4458…`
2026-08-18T05:54:09+00:00	SPF	—	VALID	`4d4815dd4357…`