feat: 添加路由装饰器系统和全局异常处理

- 新增装饰器支持(@Get, @Post, @Put, @Delete, @Patch, @Controller)
- 实现路由自动注册机制(RouteScanner)
- 添加全局异常处理中间件(Exception)
- 实现统一响应体格式(ApiResponse)
- 新增请求体解析中间件(BodyParser)
- 重构控制器为类模式，支持装饰器路由
- 添加示例用户控制器(UserController)
- 更新TypeScript配置支持装饰器
- 添加reflect-metadata依赖
- 完善项目文档

Breaking Changes:
- 控制器现在返回数据而不是直接设置ctx.body
- 新增统一的API响应格式

apps/server/controllers/user.ts

@@ -0,0 +1,117 @@
+import type { Context } from 'koa';
+import { Controller, Get, Post, Put, Delete } from '../decorators/route.ts';
+import { BusinessError } from '../middlewares/exception.ts';
+
+/**
+ * 用户控制器
+ */
+@Controller('/user')
+export class UserController {
+
+  @Get('/list')
+  async list(ctx: Context) {
+    // 模拟用户列表数据
+    const users = [
+      { id: 1, name: 'Alice', email: 'alice@example.com', status: 'active' },
+      { id: 2, name: 'Bob', email: 'bob@example.com', status: 'inactive' },
+      { id: 3, name: 'Charlie', email: 'charlie@example.com', status: 'active' }
+    ];
+
+    return users;
+  }
+
+  @Get('/detail/:id')
+  async detail(ctx: Context) {
+    const { id } = ctx.params;
+
+    // 模拟根据ID查找用户
+    const user = {
+      id: Number(id),
+      name: 'User ' + id,
+      email: `user${id}@example.com`,
+      status: 'active',
+      createdAt: new Date().toISOString()
+    };
+
+    if (Number(id) > 100) {
+      throw new BusinessError('用户不存在', 2001, 404);
+    }
+
+    return user;
+  }
+
+  @Post('')
+  async create(ctx: Context) {
+    const body = (ctx.request as any).body;
+
+    // 模拟创建用户
+    const newUser = {
+      id: Date.now(),
+      ...body,
+      createdAt: new Date().toISOString(),
+      status: 'active'
+    };
+
+    return newUser;
+  }
+
+  @Put('/:id')
+  async update(ctx: Context) {
+    const { id } = ctx.params;
+    const body = (ctx.request as any).body;
+
+    // 模拟更新用户
+    const updatedUser = {
+      id: Number(id),
+      ...body,
+      updatedAt: new Date().toISOString()
+    };
+
+    return updatedUser;
+  }
+
+  @Delete('/:id')
+  async delete(ctx: Context) {
+    const { id } = ctx.params;
+
+    if (Number(id) === 1) {
+      throw new BusinessError('管理员账户不能删除', 2002, 403);
+    }
+
+    // 模拟删除操作
+    return {
+      success: true,
+      message: `用户 ${id} 已删除`,
+      deletedAt: new Date().toISOString()
+    };
+  }
+
+  @Get('/search')
+  async search(ctx: Context) {
+    const { keyword, status } = ctx.query;
+
+    // 模拟搜索逻辑
+    let results = [
+      { id: 1, name: 'Alice', email: 'alice@example.com', status: 'active' },
+      { id: 2, name: 'Bob', email: 'bob@example.com', status: 'inactive' }
+    ];
+
+    if (keyword) {
+      results = results.filter(user =>
+        user.name.toLowerCase().includes(String(keyword).toLowerCase()) ||
+        user.email.toLowerCase().includes(String(keyword).toLowerCase())
+      );
+    }
+
+    if (status) {
+      results = results.filter(user => user.status === status);
+    }
+
+    return {
+      keyword,
+      status,
+      total: results.length,
+      results
+    };
+  }
+}