Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T02:07:24+00:00	DMARC	—	VALID	`fcef8d60c613…`
2026-08-17T02:07:24+00:00	SPF	—	VALID	`7a6254c23e3f…`