refactor(app.vue): 修复：水印高度判断_添加移动端设置

src/App.vue

@@ -3,7 +3,7 @@
     <el-watermark :font="font"
       :content="content"
       class="wm-class"
-      :class="{'wm-mobile-class': isMobile}">
+      :class="{'wm-mobile-class': isMobile()}">
       <router-view />
     </el-watermark>
   </template>
@@ -18,7 +18,6 @@ import { handleThemeStyle } from '@/utils/theme'
 import useUserStore from '@/store/modules/user'
 import { isWhiteList } from '@/permission'
 import { isMobile } from '@/utils'
-
 const route = useRoute()
 
 /*************** 水印相关 *************** */