Separate visible demand from eligible analytics cohorts

Analytics projections should distinguish visible demand from the cohort eligible for a particular metric. Records missing durable subject identity should remain visible as unknown demand but stay out of contact, SLA, completion, touch, and repeat-contact denominators that require that identity. A mutable current identifier must not silently rewrite a historical obligation.

Applicability and limits: this pattern applies when historical triggers are joined to external-provider activity. It does not make identity inferable, recover missing completion events, or enable individual attribution. A zero eligible cohort is meaningful only when excluded unknown demand is reported beside it.