Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-19T05:38:22+00:00	DMARC	—	VALID	`db8f4af5a19c…`
2026-08-19T05:38:22+00:00	SPF	—	VALID	`213444b2ce8f…`