完善订单相关逻辑和商品推荐逻辑，添加接口注释

routes/category.js

@@ -2,6 +2,45 @@ const express = require('express');
 const { getDB } = require('../database');
 const router = express.Router();
 
+
+/**
+ * @swagger
+ * /api/category:
+ *   get:
+ *     summary: 获取一级分类及其二级分类
+ *     description: 返回所有一级分类，每个一级分类包含其下的二级分类
+ *     tags: [category]
+ *     responses:
+ *       200:
+ *         description: 成功返回一级分类及其二级分类
+ *         content:
+ *           application/json:
+ *             schema:
+ *               type: object
+ *               properties:
+ *                 success:
+ *                   type: boolean
+ *                   example: true
+ *                 data:
+ *                   type: array
+ *                   items:
+ *                     type: object
+ *                     properties:
+ *                       name:
+ *                         type: string
+ *                         example: "一级分类1"
+ *                       relative:
+ *                         type: array
+ *                         items:
+ *                           type: object
+ *                           properties:
+ *                             name:
+ *                               type: string
+ *                               example: "二级分类1-1"
+ *                             img:
+ *                               type: string
+ *                               example: "https://example.com/image.jpg"
+ */
 router.get('/', async (req, res) => {
   try {
     const db = await getDB();