Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T02:03:51+00:00	DMARC	—	VALID	`14bc9eba0453…`
2026-08-17T02:03:51+00:00	SPF	—	VALID	`b4fd2fff027f…`