perf: layout显示用户信息优化

src/layout/components/sidebar/mixNav.vue

@@ -33,6 +33,7 @@ const {
   resolvePath,
   pureApp,
   username,
+  avatarsStyle,
   getDropdownItemStyle
 } = useNav();
 
@@ -166,8 +167,8 @@ function translationEn() {
       <!-- 退出登陆 -->
       <el-dropdown trigger="click">
         <span class="el-dropdown-link">
-          <img :src="avatars" />
-          <p>{{ username }}</p>
+          <img v-if="avatars" :src="avatars" :style="avatarsStyle" />
+          <p v-if="username">{{ username }}</p>
         </span>
         <template #dropdown>
           <el-dropdown-menu class="logout">