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({

frontend/src/api/auth.ts

@@ -1,4 +1,4 @@
-import request from './request'
+import type { ApiResponse } from '@/types/api'
 
 export interface LoginRequest {
   username: string
@@ -30,7 +30,7 @@ const mockUser: UserInfo = {
 
 export const authApi = {
   // 登录
-  login(data: LoginRequest): Promise<any> {
+  login(_data: LoginRequest): Promise<ApiResponse<LoginResponse>> {
     // MVP 阶段使用 Mock 数据
     return new Promise((resolve) => {
       setTimeout(() => {
@@ -48,16 +48,16 @@ export const authApi = {
   },
 
   // 登出
-  logout(): Promise<any> {
+  logout(): Promise<ApiResponse<null>> {
     return new Promise((resolve) => {
       setTimeout(() => {
-        resolve({ code: 0, message: 'success' })
+        resolve({ code: 0, message: 'success', data: null })
       }, 200)
     })
   },
 
   // 获取用户信息
-  getUserInfo(): Promise<any> {
+  getUserInfo(): Promise<ApiResponse<UserInfo>> {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve({

frontend/src/api/request.ts

@@ -1,6 +1,8 @@
-import axios from 'axios'
+import axios, { type AxiosResponse, type AxiosError } from 'axios'
 import { getToken, removeToken } from '@/utils/auth'
 import { ElMessage } from 'element-plus'
+import type { ApiResponse } from '@/types/api'
+import { codeMessageMap } from '@/types/api'
 
 const request = axios.create({
   baseURL: '/api/v1',
@@ -21,22 +23,55 @@ request.interceptors.request.use(
   }
 )
 
+/** HTTP 状态码对应的用户友好提示 */
+const httpMessageMap: Record<number, string> = {
+  400: '请求参数错误',
+  401: '未授权，请重新登录',
+  403: '没有权限执行此操作',
+  404: '请求的资源不存在',
+  408: '请求超时，请稍后重试',
+  500: '服务器内部错误',
+  502: '网关错误',
+  503: '服务暂时不可用，请稍后重试',
+}
+
+/** 根据后端错误码获取用户友好提示 */
+function getBusinessMessage(code: number, fallback?: string): string {
+  return codeMessageMap[code] || fallback || '请求失败'
+}
+
 // 响应拦截器
 request.interceptors.response.use(
-  (response) => {
+  (response: AxiosResponse<ApiResponse>) => {
     const { data } = response
     if (data.code !== 0) {
-      ElMessage.error(data.message || '请求失败')
-      return Promise.reject(new Error(data.message))
+      const message = getBusinessMessage(data.code, data.message)
+      ElMessage.error(message)
+      return Promise.reject(new Error(message))
     }
-    return data
+    return data as any
   },
-  (error) => {
-    if (error.response?.status === 401) {
-      removeToken()
-      window.location.href = '/login'
+  (error: AxiosError<ApiResponse>) => {
+    // 优先使用后端返回的错误信息
+    const backendMessage = error.response?.data?.message
+
+    if (error.response) {
+      const status = error.response.status
+
+      if (status === 401) {
+        removeToken()
+        window.location.href = '/login'
+        ElMessage.error(backendMessage || '未授权，请重新登录')
+      } else {
+        const message = backendMessage || httpMessageMap[status] || `请求失败 (${status})`
+        ElMessage.error(message)
+      }
+    } else if (error.code === 'ECONNABORTED') {
+      ElMessage.error('请求超时，请检查网络后重试')
+    } else {
+      ElMessage.error('网络连接异常，请检查网络')
     }
-    ElMessage.error(error.message || '网络错误')
+
     return Promise.reject(error)
   }
 )

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)