Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-16T22:34:35+00:00	DMARC	—	VALID	`7e927ea8e8dd…`
2026-08-16T22:34:35+00:00	SPF	—	VALID	`00ea97518abb…`