- Add stop flag monitoring loop (checks every 100ms during tool execution)
- Cancel tool task immediately when stop flag is detected
- Return cancellation message to conversation history with role=tool
- Save cancellation result: '命令执行被用户取消'
- Clean up pending tasks to prevent 'Task was destroyed but it is pending' warnings
- Fix terminal_ops.py to properly cancel stdout/stderr read tasks
Known issue: Tool result display in frontend still shows arguments instead of cancellation message when expanded
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
