refactor: 整合MCP命令到mcp目录 - 优化项目结构

- 移动MCPServerCommand.js和MCPStreamableHttpCommand.js到lib/mcp/目录
- 删除空的lib/commands/目录，避免代码分散
- 更新bin/promptx.js中的import路径指向新位置
- 统一MCP相关代码到同一目录，提升代码组织性

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/bin/promptx.js

@@ -8,8 +8,8 @@ const logger = require('../lib/utils/logger')
 // 导入锦囊框架
 const { cli } = require('../lib/core/pouch')
 // 导入MCP Server命令
-const { MCPServerCommand } = require('../lib/commands/MCPServerCommand')
-const { MCPStreamableHttpCommand } = require('../lib/commands/MCPStreamableHttpCommand')
+const { MCPServerCommand } = require('../lib/mcp/MCPServerCommand')
+const { MCPStreamableHttpCommand } = require('../lib/mcp/MCPStreamableHttpCommand')
 
 // 创建主程序
 const program = new Command()

src/lib/commands/index.js

@@ -1,7 +0,0 @@
-const { MCPServerCommand } = require('./MCPServerCommand');
-const { MCPStreamableHttpCommand } = require('./MCPStreamableHttpCommand');
-
-module.exports = {
-  MCPServerCommand,
-  MCPStreamableHttpCommand
-};