Collapse TryCompleteParentAsync (planning -> Done) and TryAdvanceImprovementParentAsync (improvement -> WaitingForReview) into one TryAdvanceParentAsync that surfaces any WaitingForChildren parent for review once all children are terminal. Planning parents no longer auto-complete. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>