Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-20T02:57:15+00:00	DMARC	—	VALID	`642a3e3e0498…`
2026-08-20T02:57:15+00:00	SPF	—	VALID	`291e37ffd96b…`