保留当前账号标题并维持账号区域三段布局

frontend/src/views/components/HomeAside/HomeAside.css

@@ -114,6 +114,13 @@
   padding: 0 4px 12px;
 }
 
+.account-caption {
+  grid-column: 1 / -1;
+  color: var(--pm-text-secondary);
+  font-size: 11px;
+  line-height: 1.4;
+}
+
 .account-name {
   overflow: hidden;
   color: var(--pm-text-primary);

frontend/src/views/components/HomeAside/HomeAside.vue

@@ -31,6 +31,7 @@
     </div>
     <div class="sidebar-footer" v-if="isLogin">
       <div class="account-identity" aria-label="当前登录账号" aria-live="polite">
+        <span class="account-caption">当前账号</span>
         <strong class="account-name" :title="currentAccount">{{ currentAccount }}</strong>
         <el-tag :type="currentRole.type" size="small" effect="light" class="account-role">
           {{ currentRole.label }}