Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T22:42:14+00:00	DMARC	—	VALID	`43f884e6b703…`
2026-08-17T22:42:14+00:00	SPF	—	VALID	`60478a7588e2…`