Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-20T06:37:04+00:00	DMARC	—	VALID	`d3bdf52db8e8…`
2026-08-20T06:37:04+00:00	SPF	—	VALID	`33caad98d232…`