feat: 退出登录去掉 /cas 前缀并新增管理员后台管理入口

- 退出登录路径由 /cas/logout 改为 /logout（Header.vue、UserInfoModal.vue 两处）
- Header 用户下拉在"系统设置"下方为管理员新增"后台管理"栏，新窗口打开 baseHost + /userbase/front/index.html
- 新增雪碧图图标 admin-backend.svg 并统一与其他菜单项图标尺寸

src/components/Header.vue

@@ -131,6 +131,10 @@
                                 <img :src="requireImg('userinfo/icon5.png')" alt="" />
                                 <span>系统设置</span>
                             </li>
+                            <li v-if="!!store.getIsAdmin" @click="linkBackendManage">
+                                <SvgIcon name="admin-backend" size="20" color="#323233" class="backend-manage-icon" />
+                                <span>后台管理</span>
+                            </li>
                             <li v-if="!!store.getIsAdmin" @click="linkLogoSetting">
                                 <img :src="requireImg('userinfo/icon3.png')" alt="" />
                                 <span>设置LOGO</span>
@@ -527,6 +531,12 @@ function linkSysSetting() {
     router.push("/syssetting");
 }
 
+function linkBackendManage() {
+    isUserInfoShow.value = false;
+    const url = `${$conf.baseHost}/userbase/front/index.html`;
+    window.open(url, "_blank");
+}
+
 async function linkLogoSetting() {
     await loadLogoList();
     isUserInfoShow.value = false;
@@ -542,7 +552,7 @@ function showUserInfo() {
 
 function logout() {
     let url = window.location.href;
-    url = "/cas/logout?service=" + url;
+    url = "/logout?service=" + url;
     url = $conf.ssoHost + url;
     if (!!window.top) window.top.location.href = url;
     else window.location.href = url;