feat: 产品/解决方案列表页描述

- 页面描述：为产品列表与解决方案列表添加页面描述
- 停产提示：在产品列表中提示停产产品使用搜索功能

app/pages/products/index.vue

@@ -1,7 +1,13 @@
 <template>
   <div class="page-container">
     <div class="page-header">
-      <h1 class="page-title">{{ $t('our-products') }}</h1>
+      <div>
+        <h1 class="page-title">{{ $t('our-products') }}</h1>
+        <p class="page-subtitle">
+          {{ $t('products-desc') }}{{ $t('find-discontinued-products') }}
+        </p>
+      </div>
+
       <app-breadcrumb class="breadcrumb" :items="breadcrumbItems" />
     </div>
     <div v-if="!pending" class="page-content">
@@ -102,13 +108,18 @@
 
   .page-header {
     display: flex;
+    margin-bottom: 1rem;
   }
 
   .page-title {
     font-size: 2rem;
     font-weight: bold;
     color: var(--el-color-primary);
-    margin-bottom: 1rem;
+  }
+
+  .page-subtitle {
+    font-size: 0.8rem;
+    color: var(--el-text-color-secondary);
   }
 
   .breadcrumb {