chore: 清理冗余配置、优化代码结构

- 移除 SSE 独立代理(VITE_APP_SSE_URL)及相关配置
- 删除 CHANGELOG.md，清理 .env 多余注释
- 重构 permission.ts 路由守卫，用 return 替代 next() 调用
- 优化 useSse.ts：合并重复逻辑、增加中文注释、调整重连参数
- 简化 vite.config.ts 代理和注释

src/router/guards/permission.ts

@@ -14,7 +14,7 @@ import { addRecentMenu } from "@/composables/useRecentMenus";
 export function setupPermissionGuard() {
   const whiteList = ["/login"];
 
-  router.beforeEach(async (to, _from, next) => {
+  router.beforeEach(async (to, _from) => {
     NProgress.start();
 
     try {
@@ -23,18 +23,15 @@ export function setupPermissionGuard() {
       // 未登录处理
       if (!isLoggedIn) {
         if (whiteList.includes(to.path)) {
-          next();
-        } else {
-          next(`/login?redirect=${encodeURIComponent(to.fullPath)}`);
-          NProgress.done();
+          return;
         }
-        return;
+        NProgress.done();
+        return `/login?redirect=${encodeURIComponent(to.fullPath)}`;
       }
 
       // 已登录访问登录页，重定向到首页
       if (to.path === "/login") {
-        next({ path: "/" });
-        return;
+        return { path: "/" };
       }
 
       const permissionStore = usePermissionStore();
@@ -54,14 +51,12 @@ export function setupPermissionGuard() {
           router.addRoute(route);
         });
 
-        next({ ...to, replace: true });
-        return;
+        return { ...to, replace: true };
       }
 
       // 路由 404 检查
       if (to.matched.length === 0) {
-        next("/404");
-        return;
+        return "/404";
       }
 
       // 动态标题
@@ -69,13 +64,11 @@ export function setupPermissionGuard() {
       if (title) {
         to.meta.title = title;
       }
-
-      next();
     } catch (error) {
       console.error("Route guard error:", error);
       await useUserStore().resetAllState();
-      next("/login");
       NProgress.done();
+      return "/login";
     }
   });