[BUG] /effort changes are instantly propagated to other running claude code sessions

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?

I use multiple claude code session at the same time(one is subscription-based and the other is api token based).

1) claude --settings ~/.claude-subscription/settings.json
2) claude --settings ~/.claude-api/settings.json

If I run /effort high or any other effort level update, it is instantly propagated to the other session.

What Should Happen?

I expect them to keep separate/independent effort level settings

Error Messages/Logs

Steps to Reproduce

explained in What's wrong

Claude Model

Not sure / Multiple models

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.76

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Xterm

Additional Information

_No response_