优化代码格式和异常处理

- 修复异常处理链，使用from语法保留原始异常
- 格式化代码以符合项目规范
- 优化导入模块的顺序

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

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

src/plugins/chat/cq_code.py

@@ -1,6 +1,5 @@
 import base64
 import html
-import time
 import asyncio
 from dataclasses import dataclass
 from typing import Dict, List, Optional, Union
@@ -26,6 +25,7 @@ ssl_context.set_ciphers("AES128-GCM-SHA256")
 
 logger = get_module_logger("cq_code")
 
+
 @dataclass
 class CQCode:
     """
@@ -91,7 +91,8 @@ class CQCode:
     async def get_img(self) -> Optional[str]:
         """异步获取图片并转换为base64"""
         headers = {
-            "User-Agent": "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.87 Safari/537.36",
+            "User-Agent": "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) "
+            "Chrome/50.0.2661.87 Safari/537.36",
             "Accept": "text/html, application/xhtml xml, */*",
             "Accept-Encoding": "gbk, GB2312",
             "Accept-Language": "zh-cn",