perf: 懒加载表现优化

- 优化路由首进页面过渡策略，减少遮罩阻塞感

- 为菜单导航增加组件预取，降低首次点击等待

- 缩短页面 loading 遮罩过渡时长

easyflow-ui-admin/app/src/router/guard.ts

@@ -10,6 +10,39 @@ import { useAuthStore } from '#/store';
 
 import { generateAccess } from './access';
 
+interface NetworkConnectionLike {
+  effectiveType?: string;
+  saveData?: boolean;
+}
+
+function isSlowNetworkConnection() {
+  if (typeof navigator === 'undefined') {
+    return false;
+  }
+  const nav = navigator as Navigator & {
+    connection?: NetworkConnectionLike;
+    mozConnection?: NetworkConnectionLike;
+    webkitConnection?: NetworkConnectionLike;
+  };
+  const connection =
+    nav.connection ?? nav.mozConnection ?? nav.webkitConnection;
+  if (!connection) {
+    return false;
+  }
+  if (connection.saveData) {
+    return true;
+  }
+  return ['2g', '3g', 'slow-2g'].includes(connection.effectiveType ?? '');
+}
+
+function shouldUseRouteProgress() {
+  if (preferences.transition.progress) {
+    return true;
+  }
+  // 普通网络下，loading遮罩不显示时自动回退到顶部进度条
+  return preferences.transition.loading && !isSlowNetworkConnection();
+}
+
 /**
  * 通用守卫配置
  * @param router
@@ -22,7 +55,7 @@ function setupCommonGuard(router: Router) {
     to.meta.loaded = loadedPaths.has(to.path);
 
     // 页面加载进度条
-    if (!to.meta.loaded && preferences.transition.progress) {
+    if (!to.meta.loaded && shouldUseRouteProgress()) {
       startProgress();
     }
     return true;
@@ -34,7 +67,7 @@ function setupCommonGuard(router: Router) {
     loadedPaths.add(to.path);
 
     // 关闭页面加载进度条
-    if (preferences.transition.progress) {
+    if (shouldUseRouteProgress()) {
       stopProgress();
     }
   });