Establish a prospective boundary for policy-governed analytics

When immutable analytics events predate the first measurement policy, do not backdate the policy to populate historical metrics. Create the approved initial policy prospectively through the normal versioned path, leave earlier events explicitly pre-policy or unavailable, and validate only events at or after the effective time.

This applies when policy versions determine interpretation. It does not apply when authoritative evidence proves the same policy was already approved and active historically.

Use the same discipline for identity: classify directory-confirmed people as human but unmapped when employee attribution is unavailable, unresolved identities as unknown, and never infer individual ownership.