[BUG] Unable to continue after Claude Code acknowledge desired interrupt

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

After I typed a prompt and hit Enter, I immediately realize I made a mistake in my observation when writing the prompt. The question is no longer irrelevant and I want claude to stop.
I type /btw I made a mistake, please stop. Claude acknowledge that and stay it's stopped.
At this time I have no way to continue, because I can't type anything more into the prompt. So I press Escape because that's the option printed on screen available to me.
As soon as I press Escape, claude continue with the original prompt and continue consuming tokens.
Again I type "/btw please stop" and it acknowledges, but again after I press Escape, it continued as if it never saw my directive to stop.

What Should Happen?

After it saw the /btw directive to stop, it should stop thinking about the original prompt immediately, and return control of the GUI prompt window back to me so I can type a new prompt. Or if I have to press Escape to go back then stop thinking after that and allow me to type new prompt.
Alternatively, if "/btw" is not the right way, then please provide a way to quickly interrupt an on-going "thinking" when the original prompt is already irrelevant.

Error Messages/Logs

Steps to Reproduce

1. Ask a question that will require some long thinking
2. Type "/btw please stop, I already know the answer"
3. Once claude code acknowledge that, press Escape to go back the prompt-typing window
4. Observe that now claude code still continue to process the original prompt and consume more tokens.

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.168

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Xterm

Additional Information

_No response_