refactor(managers): 重构单例管理器实现并优化代码结构

feat(ws_pool): 新增 WebSocket 连接池实现

perf(json): 使用 orjson 替代标准 json 库提升性能

style: 清理未使用的导入和冗余代码

docs: 更新架构文档和开发规范

test: 添加 WebSocket 连接池测试用例

fix(plugins): 修复自动审批插件 API 调用参数格式

core/managers/browser_manager.py

@@ -7,21 +7,23 @@ import asyncio
 from typing import Optional
 from playwright.async_api import async_playwright, Browser, Playwright, Page
 from ..utils.logger import logger
+from ..utils.singleton import Singleton
 
-class BrowserManager:
+class BrowserManager(Singleton):
     """
     浏览器管理器（异步单例）
     """
-    _instance = None
     _playwright: Optional[Playwright] = None
     _browser: Optional[Browser] = None
     _page_pool: Optional[asyncio.Queue] = None
     _pool_size: int = 3
 
-    def __new__(cls):
-        if cls._instance is None:
-            cls._instance = super().__new__(cls)
-        return cls._instance
+    def __init__(self):
+        """
+        初始化浏览器管理器
+        """
+        # 调用父类 __init__ 确保单例初始化
+        super().__init__()
 
     async def initialize(self):
         """