FIX[BE]Lock chickins, accumulate pending qty, use qty key

internal/modules/production/chickins/services/chickin.service.go

@@ -196,6 +196,8 @@ func (s *chickinService) CreateOne(c *fiber.Ctx, req *validation.Create) ([]enti
 			}
 		}
 
+		// CRITICAL: Validate chickins sequentially to prevent over-allocation within the same request
+		// pendingQtyMap is accumulated as we validate each chickin to ensure total pending doesn't exceed available stock
 		for idx, chickin := range newChikins {
 			pendingQty := pendingQtyMap[chickin.ProductWarehouseId]
 			desiredQty := chickinQtyMap[uint(idx)]
@@ -210,6 +212,10 @@ func (s *chickinService) CreateOne(c *fiber.Ctx, req *validation.Create) ([]enti
 			}
 
 			chickinQtyMap[uint(idx)] = availableQty
+
+			// ACCUMULATE pending for this product warehouse so NEXT chickin in same request sees it
+			// This prevents multiple chickins in same request from over-allocating the same stock
+			pendingQtyMap[chickin.ProductWarehouseId] += availableQty
 		}
 
 		approvalSvcTx := commonSvc.NewApprovalService(commonRepo.NewApprovalRepository(dbTransaction))