Boat Thinckess当累计膜厚小于等于0 时候，按照0处理

Furnace/FurnaceRT/Equipments/PMs/PMScheduleMaintenance.cs

@@ -215,8 +215,18 @@ namespace FurnaceRT.Equipments.PMs
 
             if (item != null && item.Item == MaintenanceItemEnum.BoatRecipeThickness1.ToString())
             {
-                Singleton<ScheduleMaintenanceDataManager>.Instance.Increase(item.Item, thickness);
-                SetCurrentFilmThickness(Singleton<ScheduleMaintenanceDataManager>.Instance.GetItem(item.Item).CurrentValue);
+                var currentValue = Singleton<ScheduleMaintenanceDataManager>.Instance.GetItem(item.Item).CurrentValue;
+                if ((currentValue + thickness) <= 0)
+                {
+                    Singleton<ScheduleMaintenanceDataManager>.Instance.SetValue(item.Item, 0);
+                    currentValue = 0;
+                }
+                else
+                {
+                    Singleton<ScheduleMaintenanceDataManager>.Instance.Increase(item.Item, thickness);
+                }
+                SetCurrentFilmThickness(currentValue);
+
             }
         }