fix: 提升管理端启动与导航稳定性

- 等待初始路由就绪并提供可恢复的启动失败页面

- 收敛失效登录导航并按需加载 SVG 图标资源

easyflow-ui-admin/app/src/router/navigation-user-info.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, it, vi } from 'vitest';
+
+import { resolveNavigationUserInfo } from './navigation-user-info';
+
+describe('navigation user info', () => {
+  it('uses cached user info without issuing a request', async () => {
+    const cachedUserInfo = { id: 1 };
+    const fetchUserInfo = vi.fn();
+
+    await expect(
+      resolveNavigationUserInfo({
+        cachedUserInfo,
+        fetchUserInfo,
+        getAccessToken: () => 'token',
+      }),
+    ).resolves.toBe(cachedUserInfo);
+    expect(fetchUserInfo).not.toHaveBeenCalled();
+  });
+
+  it('returns null after an expired token has been cleared', async () => {
+    await expect(
+      resolveNavigationUserInfo({
+        cachedUserInfo: null,
+        fetchUserInfo: () => Promise.reject(new Error('expired')),
+        getAccessToken: () => null,
+      }),
+    ).resolves.toBeNull();
+  });
+
+  it('keeps non-authentication failures visible', async () => {
+    const error = new Error('network unavailable');
+    await expect(
+      resolveNavigationUserInfo({
+        cachedUserInfo: null,
+        fetchUserInfo: () => Promise.reject(error),
+        getAccessToken: () => 'token',
+      }),
+    ).rejects.toBe(error);
+  });
+});