Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-19T07:42:46+00:00	DMARC	—	VALID	`c3edb95b7438…`
2026-08-19T07:42:46+00:00	SPF	—	ABSENT	`b081350f91db…`