Audit child decisions and aggregate status separately in shadow parity

In a grouped shadow migration, compare child outputs and the aggregate result separately, and distinguish freshly evaluated decisions from statuses selected for aggregation. A preservation rule can retain an older child status even when fresh evaluation agrees with legacy; conversely, an unchanged aggregate can hide a child mismatch. Normalize repeated receipts by distinct groups and split comparable from unavailable outputs before reporting agreement.

Applicability and limits: these checks identify discrepancy mechanisms, not which engine is correct. Pre-write candidate snapshots and post-write legacy results can also introduce timing differences that need separate validation, and parity does not establish live write safety.