Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-16T23:18:24+00:00	DMARC	—	VALID	`fe6a788b0dea…`
2026-08-16T23:18:24+00:00	SPF	—	VALID	`a3af6a97b80d…`