[BUG] New config does not recognise custom output-styles

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?

The depreciation of output-style has removed the ability to easily switch between custom personas and output styles. I have an entire project built around this feature and the new config does not recognise any of these custom output-styles despite them being correctly configured. Claude also has no idea on how to fix the issue.

What Should Happen?

I should be able to type /output-style and get a list of available custom styles to be honest as that was one of the most useful features in Claude but if it has to be within config it should provide the same ease of use and visibility.

Error Messages/Logs

N/A

Steps to Reproduce

1. Create custom output style in ~/.claude/output-styles/
2. Go to /config, select Output styles and observe nothing.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.74 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Please just reinstate output-style. Even if config does work, its a serious regression when compared to this super useful feature.