[BUG] selected model not clear, the statusline does not show updated model

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?

when selecting model using /model in multiple session, it is not clear which model is selected.

Picture depicts selecting sonnet 4.5 but statusline still shows Opus 4.5

<img width="596" height="795" alt="Image" src="https://github.com/user-attachments/assets/3de3807f-05ea-4151-adc0-9ea11e30da81" />

What Should Happen?

ouput of statusline, if set up, should show correct model.

Error Messages/Logs

Steps to Reproduce

1. configure a status line to show the selected model for the session
2. have multiple sessions of claude open
3. select a model in one
4. select a model in another

One of these will not have the correct StatusLine

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.76

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_