fix(HelpPage): 添加空状态显示当帮助内容为空时

@@ -10,7 +10,8 @@
     <div class="bg-gradient-to-br from-green-50 via-green-100/30 to-blue-50/30 min-h-screen">
       <div class="px-4 py-6">
         <FrostedGlass class="rounded-xl overflow-hidden">
-          <div class="divide-y divide-gray-100">
+          <!-- 有数据时显示列表 -->
+          <div v-if="helpItems.length > 0" class="divide-y divide-gray-100">
             <div
               v-for="item in helpItems"
               :key="item.id"
@@ -35,6 +36,9 @@
               </svg>
             </div>
           </div>
+          
+          <!-- 无数据时显示空状态 -->
+          <van-empty v-else description="暂无帮助内容" />
         </FrostedGlass>
       </div>
     </div>