refactor: 重构MCPOutputAdapter到mcp目录 - 优化代码组织结构

📁 目录重构
- 移动: src/lib/adapters/MCPOutputAdapter.js → src/lib/mcp/MCPOutputAdapter.js
- 删除: src/lib/adapters/ 空目录
- 整合: 所有MCP相关组件统一在mcp目录下

🔧 引用更新
Components:
- src/lib/commands/MCPServerCommand.js: 更新import路径
- src/lib/commands/MCPStreamableHttpCommand.js: 更新import路径

🎯 重构目标
- 统一MCP相关代码组织
- 提升代码可维护性
- 优化目录结构逻辑

📂 新的mcp目录结构
src/lib/mcp/
├── MCPOutputAdapter.js     # MCP输出适配器
└── toolDefinitions.js      # MCP工具定义

✅ 验证通过
- @tool://calculator 除法功能正常: 84 ÷ 2 = 42
- MCP Server功能完全正常
- 所有引用路径正确更新

💡 架构收益
- MCP组件集中管理
- 代码职责更清晰
- 便于后续MCP功能扩展

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

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

src/lib/commands/MCPServerCommand.js

@@ -1,7 +1,7 @@
 const { Server } = require('@modelcontextprotocol/sdk/server/index.js');
 const { StdioServerTransport } = require('@modelcontextprotocol/sdk/server/stdio.js');
 const { cli } = require('../core/pouch');
-const { MCPOutputAdapter } = require('../adapters/MCPOutputAdapter');
+const { MCPOutputAdapter } = require('../mcp/MCPOutputAdapter');
 const { getExecutionContext, getDebugInfo } = require('../utils/executionContext');
 const { getToolDefinitions } = require('../mcp/toolDefinitions');
 const treeKill = require('tree-kill');

src/lib/commands/MCPStreamableHttpCommand.js

@@ -5,7 +5,7 @@ const { StreamableHTTPServerTransport } = require('@modelcontextprotocol/sdk/ser
 const { SSEServerTransport } = require('@modelcontextprotocol/sdk/server/sse.js');
 const { isInitializeRequest } = require('@modelcontextprotocol/sdk/types.js');
 const { cli } = require('../core/pouch');
-const { MCPOutputAdapter } = require('../adapters/MCPOutputAdapter');
+const { MCPOutputAdapter } = require('../mcp/MCPOutputAdapter');
 const { getToolDefinitions, getToolDefinition, getToolZodSchema } = require('../mcp/toolDefinitions');
 const logger = require('../utils/logger');