修改名称，优化

cloudfunctions/createRoom/index.js

@@ -12,10 +12,14 @@ exports.main = async (event, context) => {
     const { userInfo, keywords, requirements, name, meetTime } = event
 
     try {
+        // 计算过期时间（30天后）
+        const expireTime = new Date(Date.now() + 30 * 24 * 60 * 60 * 1000)
+
         const res = await db.collection('rooms').add({
             data: {
                 _openid: openid, // 创建者openid
                 createdAt: db.serverDate(),
+                expireTime: expireTime, // 过期时间
                 status: 'active',
                 name: name || '未命名聚会',
                 meetTime: meetTime || '',