Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T13:20:07+00:00	DMARC	—	VALID	`29f8ca3cf27f…`
2026-08-21T13:20:07+00:00	SPF	—	VALID	`eb78df13cdc4…`