feat: 导航体验优化 — 控制台入口提升 + AppLayout 返回前台链接

BlogLayout 导航菜单新增"控制台"按钮（登录后可见，普通用户→控制台，管理员→管理后台），
移除下拉菜单中冗余的控制台项。AppLayout 侧边栏新增"返回首页"和"AI 助手"入口。
路由调整：根路径指向 AI 助手，/blog 指向博客首页。

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

jog-frontend/src/layouts/AppLayout.vue

@@ -3,6 +3,14 @@
     <el-container>
       <el-aside width="200px">
         <el-menu :default-active="$route.path" router>
+          <el-menu-item index="/blog">
+            <el-icon><HomeFilled /></el-icon>
+            <span>返回首页</span>
+          </el-menu-item>
+          <el-menu-item index="/">
+            <el-icon><ChatDotRound /></el-icon>
+            <span>AI 助手</span>
+          </el-menu-item>
           <el-menu-item index="/app/dashboard">
             <el-icon><DataAnalysis /></el-icon>
             <span>控制台</span>

jog-frontend/src/layouts/BlogLayout.vue

@@ -4,12 +4,15 @@
       <div class="header-content">
         <router-link to="/" class="logo">Jog</router-link>
         <el-menu mode="horizontal" :ellipsis="false" class="nav-menu">
-          <el-menu-item index="home">
-            <router-link to="/">首页</router-link>
+          <el-menu-item index="blog">
+            <router-link to="/blog">博客</router-link>
           </el-menu-item>
           <el-menu-item index="ai-assistant">
             <router-link to="/ai-assistant">AI 助手</router-link>
           </el-menu-item>
+          <el-menu-item v-if="userStore.isLoggedIn" @click="$router.push(userStore.isAdmin ? '/admin' : '/app/dashboard')">
+            控制台
+          </el-menu-item>
         </el-menu>
         <div class="header-right">
           <template v-if="userStore.isLoggedIn">
@@ -20,7 +23,6 @@
               </span>
               <template #dropdown>
                 <el-dropdown-menu>
-                  <el-dropdown-item @click="$router.push('/app/dashboard')">控制台</el-dropdown-item>
                   <el-dropdown-item v-if="userStore.isAdmin" @click="$router.push('/admin')">管理后台</el-dropdown-item>
                   <el-dropdown-item divided @click="handleLogout">退出登录</el-dropdown-item>
                 </el-dropdown-menu>

jog-frontend/src/router/index.js

@@ -19,9 +19,9 @@ const routes = [
     children: [
       {
         path: '',
-        name: 'Home',
-        component: () => import('@/views/Home.vue'),
-        meta: { title: '首页' },
+        name: 'AiAssistant',
+        component: () => import('@/views/AiAssistant.vue'),
+        meta: { title: 'AI 助手' },
       },
       {
         path: 'article/:id',
@@ -30,10 +30,10 @@ const routes = [
         meta: { title: '文章详情' },
       },
       {
-        path: 'ai-assistant',
-        name: 'AiAssistant',
-        component: () => import('@/views/AiAssistant.vue'),
-        meta: { title: 'AI 助手' },
+        path: 'blog',
+        name: 'Blog',
+        component: () => import('@/views/Home.vue'),
+        meta: { title: '博客' },
       },
     ],
   },
@@ -125,7 +125,7 @@ router.beforeEach((to, from, next) => {
   if (to.meta.requiresAuth && !token) {
     next({ name: 'Login', query: { redirect: to.fullPath } })
   } else if (to.meta.requiresAdmin && userInfo?.role !== 'ADMIN') {
-    next({ name: 'Home' })
+    next({ name: 'Blog' })
   } else {
     next()
   }