Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T14:54:45+00:00	DMARC	—	VALID	`0ef4b26e3089…`
2026-08-21T14:54:45+00:00	SPF	—	VALID	`1ff73dcee55c…`