Rebuild children only when their dependency actually changes

In a parent-child event pipeline, rebuilding every child whenever the parent receives another batch amplifies routine ingestion into historical work. A long-lived parent with many children can repeatedly refill the queue even when child source cutoffs are unchanged. Enqueue the directly changed session and explicitly return children whose previously unresolved parent relationship was repaired. Preserve same-cutoff corrections for real metadata changes; a cutoff-only deduplication rule can miss those. Separate historical recovery scheduling from live processing. This mechanism is supported by code and queue evidence, but the proposed repair still requires tests and deployment verification.

Applies when: Parent sessions accumulate children and derived views depend on repaired topology. Keywords: parent child fanout rebuild queue historical replay live backlog