fix: 商品种类放左侧，分类侧栏

src/pages/product/select.vue

@@ -14,17 +14,19 @@
       </view>
     </view>
 
-    <!-- 分类行 -->
-    <view class="category-row">
+    <!-- 分类侧栏 + 商品列表 -->
+    <view class="content-wrapper">
+      <!-- 左侧分类 -->
+      <scroll-view scroll-y class="category-sidebar">
         <view class="category-item" :class="{ active: !categoryId }" @click="selectCategory('')">
           全部
         </view>
         <view v-for="cat in categories" :key="cat.categoryId" class="category-item" :class="{ active: categoryId === cat.categoryId }" @click="selectCategory(cat.categoryId)">
           {{ cat.name }}
         </view>
-    </view>
+      </scroll-view>
 
-    <!-- 商品列表 -->
+      <!-- 右侧商品列表 -->
       <scroll-view scroll-y class="product-scroll">
         <view class="product-list">
           <view v-for="item in productList" :key="item.productId" class="product-item" @click="selectProduct(item)">
@@ -47,6 +49,7 @@
         </view>
       </view>
     </scroll-view>
+    </view>
 
     <!-- 商品详情/选择弹窗 -->
     <view class="modal-mask" v-if="showModal" @click="closeModal">
@@ -226,32 +229,37 @@ export default {
   color: #999;
 }
 
-/* 分类行 */
-.category-row {
+/* 内容区域：侧栏+列表 */
+.content-wrapper {
   display: flex;
-  background: #fff;
-  padding: 20rpx;
-  overflow-x: auto;
-  white-space: nowrap;
+  height: calc(100vh - 130rpx);
 }
 
-.category-row .category-item {
-  display: inline-block;
-  padding: 16rpx 32rpx;
+/* 分类侧栏 */
+.category-sidebar {
+  width: 160rpx;
+  background: #fff;
+  flex-shrink: 0;
+  border-right: 1rpx solid #eee;
+}
+
+.category-sidebar .category-item {
+  padding: 28rpx 16rpx;
   font-size: 26rpx;
   color: #666;
-  border-radius: 30rpx;
-  margin-right: 16rpx;
-  background: #f5f5f5;
+  text-align: center;
+  border-left: 6rpx solid transparent;
 }
 
-.category-row .category-item.active {
-  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
-  color: #fff;
+.category-sidebar .category-item.active {
+  background: #f8f9fa;
+  color: #667eea;
+  font-weight: bold;
+  border-left-color: #667eea;
 }
 
 .product-scroll {
-  height: calc(100vh - 260rpx);
+  flex: 1;
   background: #f8f9fa;
 }