[BUG] Theme auto-changed after updating to today's 2.1.158 release

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?

What's Wrong?

After updating Claude Code to today's 2.1.158 release, the configured theme changed automatically without user action.

This appears to be a regression in theme/settings persistence or migration during the update. The previously selected/default theme was not preserved after the upgrade.

What Should Happen?

Claude Code should preserve the user's existing theme setting across updates. Updating the CLI should not silently switch the theme or overwrite the selected/default theme.

Steps to Reproduce

1. Use Claude Code with a theme already configured.
2. Update Claude Code to today's 2.1.158 release.
3. Launch Claude Code again.
4. Observe that the theme has changed automatically.

Actual Behavior

The theme changed automatically after the update.

Expected Behavior

The previously configured theme should remain unchanged after updating.

Is this a regression?

Yes, this started after updating to today's 2.1.158 release.

Platform

Linux terminal.

Additional Information

No manual theme setting change was made. The change happened immediately after updating Claude Code.

What Should Happen?

Theme remains users last used

Error Messages/Logs

Steps to Reproduce

Update Claude Code to 2.1.158 from one of a previous version with theme Dark mode (ANSI colors only) ✔

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.158

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

_No response_