feat(app): 添加全局加载组件和CAS单点登录功能

- 在App.vue中引入GlobalLoading组件并挂载到全局
- 新增src/components/GlobalLoading/index.vue组件文件
- 在auth.js中添加AccessUserKey常量和相关存储方法
- 在login.js中添加logincas和outlogcas接口函数
- 在main.js中注册GlobalLoading全局组件
- 修改Navbar.vue实现CAS登出逻辑和跳转处理
- 增加sessionStorage和localStorage清理机制

Signed-off-by: NewName <1048783178@qq.com>

src/App.vue

@@ -1,19 +1,22 @@
 <template>
   <div id="app" style="background-color:#0e2e87" v-if="$route.meta.bigScreen">
     <router-view />
+    <global-loading ref="globalLoading" />
   </div>
   <div id="app" v-else>
     <router-view :key="language"/>
     <theme-picker />
+    <global-loading ref="globalLoading" />
   </div>
 </template>
 
 <script>
 import ThemePicker from "@/components/ThemePicker";
+import GlobalLoading from '@/components/GlobalLoading'
 
 export default {
   name: "App",
-  components: { ThemePicker },
+  components: { ThemePicker, GlobalLoading },
   metaInfo() {
     return {
       title: this.$store.state.settings.dynamicTitle && this.$store.state.settings.title,
@@ -26,9 +29,14 @@ export default {
     language(){
       return this.$store.state.settings.language
     }
+  },
+  mounted() {
+    // 将loading方法挂载到全局，方便在任何组件中调用
+    this.$root.$loading = this.$refs.globalLoading
   }
 };
 </script>
+
 <style scoped>
 #app .theme-picker {
   display: none;