feat(backend): implement knowledge base management backend API

backend/src/index.ts

@@ -1,10 +1,17 @@
 import Fastify from 'fastify';
 import cors from '@fastify/cors';
+import multipart from '@fastify/multipart';
 import { config, validateEnv } from './config/env.js';
 import { testDatabaseConnection, prisma } from './config/database.js';
 import { projectRoutes } from './routes/projects.js';
 import { agentRoutes } from './routes/agents.js';
 import { conversationRoutes } from './routes/conversations.js';
+import knowledgeBaseRoutes from './routes/knowledgeBases.js';
+
+// 全局处理BigInt序列化
+(BigInt.prototype as any).toJSON = function() {
+  return Number(this);
+};
 
 const fastify = Fastify({
   logger: {
@@ -26,6 +33,13 @@ await fastify.register(cors, {
   credentials: true,
 });
 
+// 注册文件上传插件
+await fastify.register(multipart, {
+  limits: {
+    fileSize: 10 * 1024 * 1024, // 10MB
+  },
+});
+
 // 健康检查路由
 fastify.get('/health', async () => {
   // 检查数据库连接
@@ -63,6 +77,9 @@ await fastify.register(agentRoutes, { prefix: '/api/v1' });
 // 注册对话管理路由
 await fastify.register(conversationRoutes, { prefix: '/api/v1' });
 
+// 注册知识库管理路由
+await fastify.register(knowledgeBaseRoutes, { prefix: '/api/v1' });
+
 // 启动服务器
 const start = async () => {
   try {