Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-16T23:29:53+00:00	DMARC	—	VALID	`e3a1d4aab17a…`
2026-08-16T23:29:53+00:00	SPF	—	VALID	`b1467fa7a131…`