Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-19T05:38:27+00:00	DMARC	—	VALID	`e25031d800ef…`
2026-08-19T05:38:27+00:00	SPF	—	VALID	`0dfb80bce2a4…`