feat: 支付闭环 + 运营助手 Tool Calling + 管理后台完善

- 支付系统：微信支付 mock 自动完成、NATIVE 扫码支付、JSAPI 集成
- 运营助手：Tool Calling 架构，19 个可执行工具，AI 驱动操作
- 角色管理：表格布局 + Dialog 表单 + 权限勾选
- 配置统一：config.ts 单一数据源
- API 审计：补齐 status toggle / comments 端点
- 暗黑模式硬件编码颜色全部替换为 CSS 变量

frontend/src/app/circles/[id]/client.tsx

@@ -4,6 +4,7 @@ import { useEffect, useState } from 'react';
 import Link from 'next/link';
 import { useParams } from 'next/navigation';
 import { Skeleton } from '@/components/ui/skeleton';
+import { API_BASE } from '@/lib/config';
 
 interface Post {
   id: number;
@@ -36,8 +37,8 @@ export default function CircleDetail() {
       if (token) headers['Authorization'] = `Bearer ${token}`;
 
       const [circleRes, postsRes] = await Promise.all([
-        fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/circles/${circleId}`, { headers }),
-        fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/circles/${circleId}/posts`, { headers }),
+        fetch(`${API_BASE}/circles/${circleId}`, { headers }),
+        fetch(`${API_BASE}/circles/${circleId}/posts`, { headers }),
       ]);
 
       if (circleRes.ok) setCircle(await circleRes.json());
@@ -47,7 +48,7 @@ export default function CircleDetail() {
       }
 
       if (token) {
-        const memRes = await fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/circles/${circleId}/membership`, {
+        const memRes = await fetch(`${API_BASE}/circles/${circleId}/membership`, {
           headers: { Authorization: `Bearer ${token}` },
         });
         if (memRes.ok) {
@@ -65,8 +66,8 @@ export default function CircleDetail() {
 
     const method = isMember ? 'POST' : 'POST';
     const url = isMember
-      ? `${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/circles/${circleId}/leave`
-      : `${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/circles/${circleId}/join`;
+      ? `${API_BASE}/circles/${circleId}/leave`
+      : `${API_BASE}/circles/${circleId}/join`;
 
     try {
       const res = await fetch(url, {
@@ -85,7 +86,7 @@ export default function CircleDetail() {
     if (!token || !formTitle || !formContent) return;
 
     try {
-      const res = await fetch(`${process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3000'}/api/v1/community/posts`, {
+      const res = await fetch(`${API_BASE}/community/posts`, {
         method: 'POST',
         headers: { Authorization: `Bearer ${token}`, 'Content-Type': 'application/json' },
         body: JSON.stringify({ title: formTitle, content: formContent, circleId }),