Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-19T23:18:03+00:00	DMARC	—	VALID	`83c07e9a0b23…`
2026-08-19T23:18:03+00:00	SPF	—	VALID	`3ffac9225bb3…`