update design

Assets/GameMain/Scripts/CustomComponent/PlayerInventory/PlayerInventoryComponent.cs

@@ -145,6 +145,12 @@ namespace GeometryTD.CustomComponent
             return _towerRosterService.ReduceTowerEndurance(towerInstanceIds, enduranceLoss);
         }
 
+        public bool TryDisassembleTower(long towerInstanceId)
+        {
+            EnsureInitialized();
+            return _towerAssemblyService.TryDisassembleTower(towerInstanceId);
+        }
+
         public bool TryGetSaleCandidate(long itemId, out PlayerInventorySaleCandidate candidate)
         {
             EnsureInitialized();

Assets/GameMain/Scripts/CustomComponent/PlayerInventory/PlayerInventoryTowerAssemblyService.cs

@@ -123,7 +123,7 @@ namespace GeometryTD.CustomComponent
             int[] values = new int[TowerLevelCount];
             for (int i = 0; i < values.Length; i++)
             {
-                values[i] = baseValue + perLevel * i;
+                values[i] = Mathf.Max(0, baseValue + perLevel * i);
             }
 
             return values;
@@ -135,7 +135,7 @@ namespace GeometryTD.CustomComponent
             float[] values = new float[TowerLevelCount];
             for (int i = 0; i < values.Length; i++)
             {
-                values[i] = baseValue + perLevel * i;
+                values[i] = Mathf.Max(0f, baseValue + perLevel * i);
             }
 
             return values;
@@ -180,5 +180,37 @@ namespace GeometryTD.CustomComponent
             _drBaseComp ??= GameEntry.DataTable.GetDataTable<DRBaseComp>();
             return _drBaseComp;
         }
+
+        public bool TryDisassembleTower(long towerInstanceId)
+        {
+            BackpackInventoryData inventory = _queryModel.Inventory;
+            if (towerInstanceId <= 0)
+            {
+                return false;
+            }
+
+            if (!_queryModel.TryGetTowerById(towerInstanceId, out TowerItemData tower) || tower == null)
+            {
+                return false;
+            }
+
+            if (!_queryModel.TryGetComponentById(inventory.MuzzleComponents, tower.MuzzleComponentInstanceId, out MuzzleCompItemData muzzleComp) ||
+                !_queryModel.TryGetComponentById(inventory.BearingComponents, tower.BearingComponentInstanceId, out BearingCompItemData bearingComp) ||
+                !_queryModel.TryGetComponentById(inventory.BaseComponents, tower.BaseComponentInstanceId, out BaseCompItemData baseComp))
+            {
+                return false;
+            }
+
+            InventoryParticipantUtility.TryRemoveParticipantTower(inventory, towerInstanceId, MaxParticipantTowerCount);
+
+            muzzleComp.IsAssembledIntoTower = false;
+            bearingComp.IsAssembledIntoTower = false;
+            baseComp.IsAssembledIntoTower = false;
+
+            inventory.Towers.Remove(tower);
+            return true;
+        }
+
+        private const int MaxParticipantTowerCount = 4;
     }
 }

Assets/GameMain/Scripts/Definition/InventoryRarityRuleService.cs

@@ -24,8 +24,8 @@ namespace GeometryTD.Definition
             int normalizedBase = (int)NormalizeComponentRarity(baseRarity);
 
             float average = (normalizedMuzzle + normalizedBearing + normalizedBase) / 3f;
-            int rounded = Mathf.RoundToInt(average);
-            int clamped = Mathf.Clamp(rounded, (int)RarityType.White, (int)RarityType.Red);
+            int floored = Mathf.FloorToInt(average);
+            int clamped = Mathf.Clamp(floored, (int)RarityType.White, (int)RarityType.Red);
             return (RarityType)clamped;
         }
     }