refactor(product-monitor): 优化 SKU 展示逻辑

- 添加判断，当所有 SKU都为空时显示 "-"
- 保持每个 SKU 的样式和复制功能不变

src/views/product-manage/product-monitor/component/DataTableSlot.vue

@@ -68,20 +68,25 @@ function goto() {
       <ProductInfo :img-width="60" :item="row.goods" />
     </div>
     <div v-else-if="field === 'sku'" style="color: #1d2129;">
-      <div v-if="row.goods.sku" class="flex items-center justify-center max-h-5">
-        {{ row.goods.sku }}
-        <el-button :icon="CopyDocument" class="ml-1 cursor-pointer" link @click="handleCopy(row.goods.sku || '')">
-        </el-button>
-      </div>
-      <div v-if="row.goods.sku2" class="flex items-center justify-center max-h-5">
-        {{ row.goods.sku2 }}
-        <el-button :icon="CopyDocument" class="ml-1 cursor-pointer" link @click="handleCopy(row.goods.sku2 || '')">
-        </el-button>
+      <div v-if="row.goods.sku || row.goods.sku2 || row.goods.sku3" class="flex items-center justify-center max-h-5">
+        <div v-if="row.goods.sku">
+          {{ row.goods.sku }}
+          <el-button :icon="CopyDocument" class="ml-1 cursor-pointer" link
+                     @click="handleCopy(row.goods.sku || '')"></el-button>
+        </div>
+        <div v-if="row.goods.sku2">
+          {{ row.goods.sku2 }}
+          <el-button :icon="CopyDocument" class="ml-1 cursor-pointer" link
+                     @click="handleCopy(row.goods.sku2 || '')"></el-button>
+        </div>
+        <div v-if="row.goods.sku3">
+          {{ row.goods.sku3 }}
+          <el-button :icon="CopyDocument" class="ml-1 cursor-pointer" link
+                     @click="handleCopy(row.goods.sku3 || '')"></el-button>
+        </div>
       </div>
-      <div v-if="row.goods.sku3" class="flex items-center justify-center max-h-5">
-        {{ row.goods.sku3 }}
-        <el-button :icon="CopyDocument" class="ml-1 cursor-pointer" link @click="handleCopy(row.goods.sku3 || '')">
-        </el-button>
+      <div v-else>
+        -
       </div>
     </div>
     <div v-else-if="field === 'country_code'">