Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T20:07:49+00:00	DMARC	—	VALID	`7bf2a689f3c3…`
2026-08-21T20:07:49+00:00	SPF	—	VALID	`1ff73dcee55c…`