fix(firstleg): retry chained remainder settlement

firstleg/src/main/java/com/baiyue/firstleg/service/PdaPickSettlementService.java

@@ -169,6 +169,13 @@ public class PdaPickSettlementService {
         int sequence = splits.nextSplitSequence(parent.tenantId(), rootInboundId);
         String remainderChildCode = childPackageCount > 0
             ? childInboundCode(root.inboundCode(), sequence) : null;
+        // Consume the current slice before inserting its successor so the single-active-remainder
+        // constraint is released. A local failure rolls this back; the Order split is idempotent on retry.
+        requireAffected(splits.markSourceLoaded(parent.tenantId(), parentInboundId, pickedPackageCount,
+            operatorId, sourceVersion), "来源分片状态");
+        if (parentInboundId != rootInboundId) {
+            requireAffected(splits.touchRootSplit(parent.tenantId(), rootInboundId, operatorId, rootVersion), "根单拆分状态");
+        }
         if (remainderChildId != 0L) {
             requireAffected(splits.cloneChildWithPurpose(parent.tenantId(), parentInboundId, rootInboundId, remainderChildId,
                 orderSplit.remainderChild().orderId(), orderSplit.remainderChild().orderNo(),
@@ -198,11 +205,6 @@ public class PdaPickSettlementService {
                 line.remainingPackageCount()), "子入库测量明细");
             lineNo++;
         }
-        requireAffected(splits.markSourceLoaded(parent.tenantId(), parentInboundId, pickedPackageCount,
-            operatorId, sourceVersion), "来源分片状态");
-        if (parentInboundId != rootInboundId) {
-            requireAffected(splits.touchRootSplit(parent.tenantId(), rootInboundId, operatorId, rootVersion), "根单拆分状态");
-        }
         requireAffected(splits.applyBatch(parent.tenantId(), batchId), "拆分批次生效");
         for (MeasurementSplitLine line : measurementLines) {
             requireAffected(splits.updateMeasurementItemForLoaded(parent.tenantId(),