[BUG] No option to select `/effort` with AWS Bedrock

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?

Today's release adds support for configuring /effort for Opus 4.5 and 4.6, but I don't see any option to set /effort when I use Claude Code with Bedrock.

What Should Happen?

Claude Code with AWS Bedrock should allow users to set their /effort.

Error Messages/Logs

Steps to Reproduce

1. Install Claude Code and set it to use AWS Bedrock
2. Select Opus 4.5/4.6 as your model
3. Try typing /effort or using the left/right arrows in the model selector

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

v2.1.32

Platform

AWS Bedrock

Operating System

macOS

Terminal/Shell

Warp

Additional Information

_No response_