重构

- 统一 ItemDescForm/RewardItem/GoodsItem 的描述格式
- 减少组件属性的 Clone 数量，目前只在合并仓库、组装防御塔时才进行复制
- 删除先前留下的冗余 fallback 代码

Assets/GameMain/Scripts/UI/Shop/Controller/ShopFormController.cs

@@ -148,8 +148,8 @@ namespace GeometryTD.UI
                         GoodsIndex = item?.GoodsIndex ?? i,
                         Title = item?.Title ?? string.Empty,
                         TypeText = item?.TypeText ?? string.Empty,
-                        Description = item?.Description ?? string.Empty,
-                        TagTexts = BuildTagTexts(item?.Tags),
+                        Description = BuildDescription(item),
+                        TagTexts = BuildTagTexts(item),
                         PurchaseButtonText = item != null && item.IsPurchased ? "已购买" : $"购买 {item?.Price ?? 0}",
                         CanPurchase = item != null && !item.IsPurchased,
                         IconAreaContext = item?.IconAreaContext
@@ -164,9 +164,26 @@ namespace GeometryTD.UI
             };
         }
 
-        private static string[] BuildTagTexts(TagType[] tags)
+        private static string BuildDescription(GoodsItemRawData rawData)
         {
-            return TagDisplayUtility.BuildTagTexts(tags);
+            string baseDescription = rawData?.Description ?? string.Empty;
+            string tagDescription = TagDisplayUtility.BuildTagDescriptionText(rawData?.Tags);
+            if (string.IsNullOrWhiteSpace(tagDescription))
+            {
+                return baseDescription;
+            }
+
+            if (string.IsNullOrWhiteSpace(baseDescription))
+            {
+                return tagDescription;
+            }
+
+            return $"{baseDescription}\n{tagDescription}";
+        }
+
+        private static string[] BuildTagTexts(GoodsItemRawData rawData)
+        {
+            return TagDisplayUtility.BuildTagTexts(rawData?.Tags);
         }
     }
 }