[BUG] Effort slider non-functional in desktop app (terminal works)

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?

Title: Effort slider non-functional in desktop app (terminal works)

Body:

What happened

The effort-level slider in the Claude desktop app no longer responds. Dragging/clicking the slider has no effect — the setting does not change. This is a recent regression; it worked previously.

Changing effort from the terminal/CLI (/effort) still works correctly, so the issue appears to be isolated to the desktop app's UI control rather than the underlying setting.

Steps to reproduce

1. Open the Claude desktop app
2. Open the effort setting and attempt to change it via the slider
3. Observe that the slider does not move / the effort level does not update

Expected

The slider changes the effort level, matching the behavior available in the terminal.

Actual

The slider is unresponsive; effort cannot be changed from the desktop app. The terminal (/effort) is the only working path.

Environment

• Desktop app version: 1.14271.0
• Claude Code CLI version: 2.1.185
• OS: macOS (Darwin 25.5.0)

Notes

• Workaround: set effort via the terminal /effort command, or set "effortLevel" directly in ~/.claude/settings.json.
• Regression — this was working in a prior version.

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Post it at [github.com/anthropics/claude-code/issues](https://github.com/anthropics/claude-code/issues). Want me to adjust the tone, add a screenshot placeholder, or tighten it up?

What Should Happen?

What happened
The effort-level slider in the Claude desktop app no longer responds. Dragging/clicking the slider has no effect — the setting does not change. This is a recent regression; it worked previously.

Changing effort from the terminal/CLI (/effort) still works correctly, so the issue appears to be isolated to the desktop app's UI control rather than the underlying setting.

Steps to reproduce
Open the Claude desktop app
Open the effort setting and attempt to change it via the slider
Observe that the slider does not move / the effort level does not update
Expected
The slider changes the effort level, matching the behavior available in the terminal.

Actual
The slider is unresponsive; effort cannot be changed from the desktop app. The terminal (/effort) is the only working path.

Environment
Desktop app version: 1.14271.0
Claude Code CLI version: 2.1.185
OS: macOS (Darwin 25.5.0)
Notes
Workaround: set effort via the terminal /effort command, or set "effortLevel" directly in ~/.claude/settings.json.
Regression — this was working in a prior version.

Error Messages/Logs

Steps to Reproduce

Open the Claude desktop app
Open the effort setting and attempt to change it via the slider
Observe that the slider does not move / the effort level does not update

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.185

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

<img width="255" height="138" alt="Image" src="https://github.com/user-attachments/assets/8715049a-e89e-4388-8fce-7a8c0e306e91" />