fix: 更新 preview 的 nav 栏

- 解决 preview nav没有标题的问题

src/router/index.ts

@@ -48,7 +48,9 @@ const router = createRouter({
     {
       path: '/preview',
       name: 'preview',
-      meta: {},
+      meta: {
+        title: '预览'
+      },
       component: () => import('@/views/Survey/views/Preview/Index.vue')
     },
     {