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/audit.ts

@@ -1,4 +1,4 @@
-import request from './request'
+import type { ApiResponse, PaginatedData } from '@/types/api'
 
 export interface LoginAudit {
   id: number
@@ -39,7 +39,7 @@ const mockOpsAudits: OpsAudit[] = [
 
 export const auditApi = {
   // 获取登录审计
-  getLoginAudit(params?: any): Promise<any> {
+  getLoginAudit(_params?: any): Promise<ApiResponse<PaginatedData<LoginAudit>>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve({
@@ -55,7 +55,7 @@ export const auditApi = {
   },
 
   // 获取运维操作审计
-  getOpsAudit(params?: any): Promise<any> {
+  getOpsAudit(_params?: any): Promise<ApiResponse<PaginatedData<OpsAudit>>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve({