Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-17T01:42:35+00:00	DMARC	—	VALID	`f4f68117e6cc…`
2026-08-17T01:42:35+00:00	SPF	—	VALID	`d5913fbe3a56…`