refactor(frontend): P0 API 层收口与 http 统一

- 统一 http.ts baseURL：get/post/download/upload 均走 resolveApiUrl
- agentUtils 下沉至 lib/agent-utils，API 层移除对 components 的依赖
- 扩展 metricsApi/snmpApi/prometheusProxyApi/zabbixProxyApi
- 扩展 pipelineApi/credentialApi 覆盖流水线与凭证场景
- 14 个组件/页面禁止直连 http，统一走 @/services/api

frontend/src/pages/ApprovalWorkflowPage.tsx

@@ -7,7 +7,7 @@ import {
 import { Card, CardContent } from '@/components/ui/card';
 import { Button } from '@/components/ui/button';
 import { toast } from 'sonner';
-import { http } from '@/services/http';
+import { approvalWorkflowApi, userApi } from '@/services/api';
 
 /* ------------------------------------------------------------------ */
 /*  Types                                                               */
@@ -80,16 +80,7 @@ const STEP_TYPES = [
   { value: 'execute' as const, label: '执行阶段', desc: '执行人员操作' },
 ];
 
-// API helpers
-const workflowApi = {
-  list: (params?: { category?: string }) => http.get('/approval-workflows', params),
-  get: (id: number) => http.get(`/approval-workflows/${id}`),
-  create: (data: any) => http.post('/approval-workflows', data),
-  update: (id: number, data: any) => http.put(`/approval-workflows/${id}`, data),
-  delete: (id: number) => http.delete(`/approval-workflows/${id}`),
-  setDefault: (id: number) => http.put(`/approval-workflows/${id}/default`),
-};
-const userListApi = () => http.get('/admin/users');
+
 
 /* ------------------------------------------------------------------ */
 /*  UserSelectInline                                                    */
@@ -299,9 +290,9 @@ function WorkflowEditorModal({ workflow, users, onClose, onSaved }: EditorProps)
         })),
       };
       if (isEdit && workflow) {
-        await workflowApi.update(workflow.id, payload);
+        await approvalWorkflowApi.update(workflow.id, payload);
       } else {
-        await workflowApi.create(payload);
+        await approvalWorkflowApi.create(payload);
       }
       onSaved();
     } catch (e: unknown) {
@@ -459,7 +450,7 @@ export default function ApprovalWorkflowPage() {
     try {
       setLoading(true);
       setError(null);
-      const res: any = await workflowApi.list();
+      const res: any = await approvalWorkflowApi.list();
       const data = Array.isArray(res?.list) ? res.list : (Array.isArray(res) ? res : []);
       const normalized = data.map((w: any) => ({ ...w, steps: w.steps || [] }));
       setItems(normalized);
@@ -472,7 +463,7 @@ export default function ApprovalWorkflowPage() {
 
   const fetchUsers = useCallback(async () => {
     try {
-      const res: any = await userListApi();
+      const res: any = await userApi.getUsers();
       const data = Array.isArray(res?.list) ? res.list : (Array.isArray(res) ? res : []);
       // Normalize: extract role code from roles array
       const normalized = data.map((u: any) => ({
@@ -490,7 +481,7 @@ export default function ApprovalWorkflowPage() {
 
   const toggleActive = useCallback(async (wf: WorkflowItem) => {
     try {
-      await workflowApi.update(wf.id, { is_active: !wf.is_active });
+      await approvalWorkflowApi.update(wf.id, { is_active: !wf.is_active });
       setItems((prev) => prev.map((w) => (w.id === wf.id ? { ...w, is_active: !w.is_active } : w)));
       toast.success(wf.is_active ? '已停用' : '已启用');
     } catch { toast.error('操作失败'); }
@@ -499,7 +490,7 @@ export default function ApprovalWorkflowPage() {
   const handleDelete = useCallback(async (id: number, name: string) => {
     if (!window.confirm(`确定删除审批流程「${name}」？删除后不可恢复。`)) return;
     try {
-      await workflowApi.delete(id);
+      await approvalWorkflowApi.delete(id);
       setItems((prev) => prev.filter((w) => w.id !== id));
       toast.success('已删除');
     } catch { toast.error('删除失败'); }
@@ -507,7 +498,7 @@ export default function ApprovalWorkflowPage() {
 
   const setDefault = useCallback(async (id: number) => {
     try {
-      await workflowApi.setDefault(id);
+      await approvalWorkflowApi.setDefault(id);
       setItems((prev) => prev.map((w) => ({ ...w, is_default: w.id === id })));
       toast.success('已设为默认');
     } catch { toast.error('操作失败'); }

frontend/src/pages/MetricsExplorer.tsx

@@ -5,7 +5,7 @@ import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
 import { Activity, Search, Filter, BarChart3, Cpu, HardDrive, Network, Database, Plus } from 'lucide-react';
-import { http } from '@/services/http';
+import { metricsApi } from '@/services/api';
 
 interface _MetricName {
   name: string;
@@ -51,7 +51,7 @@ export function MetricsExplorer() {
   // Load targets
   const loadTargets = useCallback(async () => {
     try {
-      const res: Record<string, any> = await http.get('/metrics/targets?page_size=200');
+      const res: Record<string, any> = await metricsApi.getTargets({ page_size: 200 });
       setTargets(res?.list || []);
     } catch { /* empty */ }
     finally { setLoading(false); }
@@ -60,7 +60,7 @@ export function MetricsExplorer() {
   // Load metric names
   const loadMetricNames = useCallback(async () => {
     try {
-      const names: any = await http.get('/metrics/names');
+      const names: any = await metricsApi.getNames();
       setMetricNames(names || []);
     } catch { /* empty */ }
   }, []);
@@ -78,7 +78,7 @@ export function MetricsExplorer() {
 
     Promise.all(
       selectedMetrics.map(mn =>
-        http.get('/metrics/query', { target_id: selectedTarget, metric_name: mn, from: String(from), to: String(to), limit: 200 })
+        metricsApi.query({ target_id: selectedTarget, metric_name: mn, from: String(from), to: String(to), limit: 200 })
           .then(( data: any) => (Array.isArray(data) ? data : []))
           .catch(() => [])
       )

frontend/src/pages/MiddlewareMonitor.tsx

@@ -3,7 +3,7 @@ import { useState, useEffect, useCallback } from 'react';
 import { Card, CardContent } from '@/components/ui/card';
 import { Badge } from '@/components/ui/badge';
 import { Database, Server, Activity, Loader2, Circle } from 'lucide-react';
-import { http } from '@/services/http';
+import { metricsApi } from '@/services/api';
 
 interface TargetInfo {
   id: number;
@@ -68,7 +68,7 @@ export function MiddlewareMonitor() {
     try {
       setLoading(true);
       setError('');
-      const data = await http.get<TargetsResponse>('/metrics/targets', { type: 'middleware', page_size: 200 });
+      const data = await metricsApi.getTargets({ type: 'middleware', page_size: 200 }) as TargetsResponse;
       setTargets(data?.list || []);
     } catch (err: any) {
       setError((err as Record<string, any>).message || '加载失败');

frontend/src/pages/SNMPMonitor.tsx

@@ -30,7 +30,7 @@ import {
   TableRow,
 } from '@/components/ui/table';
 import { Radio, Router, HardDrive, Plus, Trash2 } from 'lucide-react';
-import http from '@/services/http';
+import { snmpApi } from '@/services/api';
 
 // ---------- types ----------
 interface SnmpStats {
@@ -81,7 +81,7 @@ export function SNMPMonitor() {
   // ---------- data fetching ----------
   const loadStats = useCallback(async () => {
     try {
-      const data = await http.get<SnmpStats>('/snmp/stats');
+      const data = await snmpApi.getStats() as SnmpStats;
       setStats(data);
     } catch {
       // backend unavailable — leave defaults
@@ -90,7 +90,7 @@ export function SNMPMonitor() {
 
   const loadDevices = useCallback(async () => {
     try {
-      const data = await http.get<DeviceListResponse>('/snmp/devices');
+      const data = await snmpApi.getDevices() as DeviceListResponse;
       setDevices(data.list ?? []);
     } catch {
       setDevices([]);
@@ -113,7 +113,7 @@ export function SNMPMonitor() {
     if (!form.name.trim() || !form.ip.trim()) return;
     setSubmitting(true);
     try {
-      await http.post('/snmp/devices', {
+      await snmpApi.createDevice({
         name: form.name.trim(),
         ip: form.ip.trim(),
         port: Number(form.port),
@@ -133,7 +133,7 @@ export function SNMPMonitor() {
 
   const handleDelete = async (id: number) => {
     try {
-      await http.delete(`/snmp/devices/${id}`);
+      await snmpApi.deleteDevice(id);
       refresh();
     } catch {
       // silently fail