Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-21T00:18:03+00:00	DMARC	—	VALID	`5e491a2b7938…`
2026-08-21T00:18:03+00:00	SPF	—	INVALID	`e303379716b8…`