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

backend/src/modules/admin/admin.controller.ts

@@ -1,10 +1,12 @@
-import { Controller, Post, Get, Put, Body, UseGuards, Req, Param } from '@nestjs/common';
+import { Controller, Post, Get, Put, Body, UseGuards, Req, Param, HttpException, HttpStatus } from '@nestjs/common';
 import { ApiTags, ApiBearerAuth } from '@nestjs/swagger';
 import { AuthGuard } from '@nestjs/passport';
 import { AdminService } from './admin.service';
 import { AdminGuard } from './admin.guard';
 import { CoursesService } from '../courses/courses.service';
 import { PrismaService } from '../../prisma/prisma.service';
+import { AIGatewayService } from '../ai/ai-gateway.service';
+import { AdminAiAssistantService } from './ai-assistant.service';
 
 @ApiTags('管理后台')
 @Controller('admin')
@@ -13,6 +15,8 @@ export class AdminController {
     private adminService: AdminService,
     private coursesService: CoursesService,
     private prisma: PrismaService,
+    private aiGateway: AIGatewayService,
+    private aiAssistant: AdminAiAssistantService,
   ) {}
 
   @Post('login')
@@ -83,4 +87,36 @@ export class AdminController {
     });
     return { ok: true };
   }
+
+  @Post('ai-assistant/chat')
+  @UseGuards(AuthGuard('jwt'), AdminGuard)
+  @ApiBearerAuth()
+  async aiAssistantChat(@Body() body: { messages: { role: string; content: string }[] }) {
+    try {
+      const { messages } = body;
+      const apiMessages = messages.map(m => ({ role: m.role as 'user' | 'assistant' | 'system', content: m.content }));
+      const reply = await this.aiGateway.chat('general', apiMessages, { temperature: 0.7, max_tokens: 2000 });
+      return { reply };
+    } catch (err: any) {
+      throw new HttpException(err.message || 'AI 助手请求失败', HttpStatus.INTERNAL_SERVER_ERROR);
+    }
+  }
+
+  @Post('ai-assistant/action')
+  @UseGuards(AuthGuard('jwt'), AdminGuard)
+  @ApiBearerAuth()
+  async aiAssistantAction(@Body() body: { tool: string; params: Record<string, any>; messages: { role: string; content: string }[] }) {
+    const result = await this.aiAssistant.execute({ tool: body.tool, params: body.params });
+    try {
+      const apiMessages = [
+        { role: 'system' as const, content: '你是一个管理后台助手。下面是对用户请求的执行结果，请用自然语言总结给用户，语言简洁。' },
+        ...body.messages.map(m => ({ role: m.role as 'user' | 'assistant', content: m.content })),
+        { role: 'assistant' as const, content: `【工具执行结果】\n工具: ${body.tool}\n参数: ${JSON.stringify(body.params)}\n结果: ${result.summary}\n数据: ${JSON.stringify(result.data)}` },
+      ];
+      const reply = await this.aiGateway.chat('general', apiMessages, { temperature: 0.3, max_tokens: 1000 });
+      return { reply, result };
+    } catch {
+      return { reply: result.summary, result };
+    }
+  }
 }