Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-18T15:07:32+00:00	DMARC	—	VALID	`1bfa6ede4058…`
2026-08-18T15:07:32+00:00	SPF	—	VALID	`ff1632a2dcd5…`