refactor(frontend): services/api 迁至 src/api，http 迁至 utils/request

对齐 Vue 后台惯例：
- src/api/          域 API（原 services/api）
- src/utils/request.ts  HTTP 封装（原 services/http.ts）
- src/utils/export.ts  客户端导出工具
- src/utils/index.ts   工具统一出口

全局导入改为 @/api 与 @/utils/request，tsc + build 通过。

frontend/src/api/cloud.ts

@@ -0,0 +1,106 @@
+// 云账号/平台/账单
+// 从 services/api.ts 拆分 — Q3 api.ts 模块化
+
+import { http, type ListResponse } from '@/utils/request';
+
+export const cloudApi = {
+  getAccounts: async () => {
+    return http.get<ListResponse>('/cloud-accounts');
+  },
+  createAccount: async ( data: any) => {
+    return http.post('/cloud-accounts', data);
+  },
+  updateAccount: async (id: number | string, data: any) => {
+    return http.put(`/cloud-accounts/${id}`, data);
+  },
+  deleteAccount: async (id: number | string) => {
+    return http.delete(`/cloud-accounts/${id}`);
+  },
+  // ==================== 云同步 API ====================
+  // 同步云账号的区域列表到本地
+  syncRegions: async (id: number | string) => {
+    return http.post(`/cloud-accounts/${id}/sync-regions`);
+  },
+  // 获取云账号的区域列表
+  getAccountRegions: async (id: number | string) => {
+    return http.get<ListResponse>(`/cloud-accounts/${id}/regions`);
+  },
+  // 发现指定区域的云主机实例
+  discoverInstances: async (id: number | string, regions: string[]) => {
+    return http.post<{ list: any[]; total: number; errors: string[] }>(`/cloud-accounts/${id}/discover-instances`, { regions });
+  },
+  // 导入选中的云主机实例为本地服务器
+  importInstances: async (id: number | string, instances: any[], opts?: { default_port?: number; credential_id?: number }) => {
+    return http.post<{ imported: number; skipped: number }>(`/cloud-accounts/${id}/import-instances`, { instances, ...opts });
+  },
+  getDomains: async (params?: { page?: number; page_size?: number; keyword?: string }) => {
+    return http.get<ListResponse>('/domains', params);
+  },
+  createDomain: async ( data: any) => {
+    return http.post('/domains', data);
+  },
+  updateDomain: async (id: number | string, data: any) => {
+    return http.put(`/domains/${id}`, data);
+  },
+  deleteDomain: async (id: number | string) => {
+    return http.delete(`/domains/${id}`);
+  },
+};
+
+// ==================== 云平台 API ====================
+
+export const platformApi = {
+  list: async () => {
+    return http.get<ListResponse>('/platforms');
+  },
+  create: async ( data: any) => {
+    return http.post('/platforms', data);
+  },
+  update: async (id: number | string, data: any) => {
+    return http.put(`/platforms/${id}`, data);
+  },
+  delete: async (id: number | string) => {
+    return http.delete(`/platforms/${id}`);
+  },
+};
+
+// ==================== 云账单 API ====================
+
+export const billingApi = {
+  getStats: async () => {
+    return http.get('/cloud-billings/stats');
+  },
+  list: async (params?: { provider?: string; start_date?: string; end_date?: string; page?: number; page_size?: number }) => {
+    return http.get<ListResponse>('/cloud-billings', params);
+  },
+  create: async ( data: any) => {
+    return http.post('/cloud-billings', data);
+  },
+  batchCreate: async ( records: any[]) => {
+    return http.post('/cloud-billings/batch', { records });
+  },
+  remove: async (id: number | string) => {
+    return http.delete(`/cloud-billings/${id}`);
+  },
+  getProviders: async () => {
+    return http.get('/cloud-billings/providers');
+  },
+  // 预警规则
+  listAlertRules: async () => {
+    return http.get<ListResponse>('/billing-alerts');
+  },
+  createAlertRule: async ( data: any) => {
+    return http.post('/billing-alerts', data);
+  },
+  updateAlertRule: async (id: number | string, data: any) => {
+    return http.put(`/billing-alerts/${id}`, data);
+  },
+  deleteAlertRule: async (id: number | string) => {
+    return http.delete(`/billing-alerts/${id}`);
+  },
+  toggleAlertRule: async (id: number | string) => {
+    return http.post(`/billing-alerts/${id}/toggle`);
+  },
+};
+
+// ==================== Agent 监控 API ====================