Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-16T22:45:09+00:00	DMARC	—	VALID	`16689b6d0a39…`
2026-08-16T22:45:09+00:00	SPF	—	VALID	`5b93ea2008cd…`