[BUG] Character from numpad are encoded weirdly

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?

After upgrading Claude to version 2.1.5, the editor in terminal use weird encoding for number and special char that come from the numpad.

Let's say I wrote Test 1234=/ using only the main part the keyboard, everything work well, but If I type numbers and equal and slash with the numpad, I got this result Test [57400u[57401u[57402u[57403u[57415u[57410u.

I think there is no impact on the prompt result but it's still very unconfortable, except when typing command, it doesn't work with a proper / ([57410u doesn't work).

I need to mention it was working well on older Claude version and it's not about my keyboard config, as writing in iTerm doesn't have this behavior.

What Should Happen?

The text shown in the terminal should be clear text like it was in previous version.

Error Messages/Logs

Steps to Reproduce

Just type in the editor with the keyboard numpad.

Environment:

• MacOS 15.7.3
• iTerm 3.6.6
• Claude Code 2.1.5
• Keyboard: Apple Keyboard with US layout

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.5

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_