fix: Update type hints to use newer Python syntax

- Replace Dict, List, Optional with dict, list,  < /dev/null |  None syntax
- Fix abstract method implementation in message.py
- Improve type annotations and function return types
- Remove unreachable code in get_current_task_tool.py
- Refactor HTML elements to use style attributes

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

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

src/do_tool/tool_use.py

@@ -106,7 +106,6 @@ class ToolUser:
 
         Args:
             message_txt: 用户消息文本
-            sender_name: 发送者名称
             chat_stream: 聊天流对象
             observation: 观察对象（可选）