增加饲喂计划列表展示界面

frontend/src/pages/Device.vue

@@ -8,6 +8,14 @@
       </div>
     </header>
 
+    <nav class="nav">
+      <ul>
+        <li><router-link to="/dashboard">控制台</router-link></li>
+        <li><router-link to="/device" class="active">设备管理</router-link></li>
+        <li><router-link to="/feed/plan">饲喂计划</router-link></li>
+      </ul>
+    </nav>
+
     <main class="main-content">
       <div class="toolbar">
         <button class="btn btn-primary" @click="openAddDeviceModal">添加设备</button>
@@ -481,6 +489,39 @@ export default {
   background-color: #f5f7fa;
 }
 
+.nav {
+  background-color: #343a40;
+  padding: 0;
+  margin-bottom: 20px;
+}
+
+.nav ul {
+  list-style-type: none;
+  margin: 0;
+  padding: 0;
+  display: flex;
+}
+
+.nav li {
+  margin: 0;
+}
+
+.nav a {
+  display: block;
+  padding: 15px 20px;
+  color: #fff;
+  text-decoration: none;
+  transition: background-color 0.3s;
+}
+
+.nav a:hover {
+  background-color: #495057;
+}
+
+.nav a.active {
+  background-color: #007bff;
+}
+
 .header {
   background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
   color: white;