feat(frontend): 对接后端统一响应格式，增强错误处理

- 新增 types/api.ts，定义 ApiResponse/PaginatedData 泛型类型和业务错误码常量
- 增强 request.ts 拦截器：提取后端错误信息、映射 HTTP 状态码和业务错误码为中文提示
- 为 auth/audit/subsystem API 添加泛型返回类型
- 为各视图添加 try/catch 防止未处理的 Promise 拒绝

frontend/src/api/subsystem.ts

@@ -1,4 +1,4 @@
-import request from './request'
+import type { ApiResponse } from '@/types/api'
 
 export interface Subsystem {
   id: number
@@ -10,6 +10,11 @@ export interface Subsystem {
   sso_enabled: boolean
 }
 
+export interface SSOResponse {
+  sso_url: string
+  expires_in: number
+}
+
 // Mock 数据
 const mockSubsystems: Subsystem[] = [
   {
@@ -70,7 +75,7 @@ const mockSubsystems: Subsystem[] = [
 
 export const subsystemApi = {
   // 获取子系统列表
-  getSubsystems(): Promise<any> {
+  getSubsystems(): Promise<ApiResponse<Subsystem[]>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve({
@@ -83,7 +88,7 @@ export const subsystemApi = {
   },
 
   // 获取 SSO 跳转 URL
-  getSSOUrl(id: number): Promise<any> {
+  getSSOUrl(id: number): Promise<ApiResponse<SSOResponse>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         const subsystem = mockSubsystems.find((s) => s.id === id)