Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-16T22:03:59+00:00	DMARC	—	VALID	`3a06f2474ac6…`
2026-08-16T22:03:59+00:00	SPF	—	VALID	`0a9b6dfdea37…`