Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T04:53:33+00:00	DMARC	—	VALID	`7190d5f91e9b…`
2026-08-17T04:53:33+00:00	SPF	—	VALID	`7fd65160122d…`