[BUG] Backspace deletes entire word instead of single character in chat input on Windows

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?

In the Claude Code chat input on Windows, pressing Backspace deletes the entire previous word instead of just the last character. This makes it very difficult to edit messages in the chat prompt.

The issue only occurs in Claude Code's chat input — other applications (VS Code, browser, Notepad) handle Backspace correctly on the same machine.

What Should Happen?

Pressing Backspace should delete only the last typed character, not the entire preceding word.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code in the VS Code integrated terminal on Windows
2. Type any multi-word text in the chat input, e.g.: hello world
3. Press Backspace once
4. Observe: world is deleted entirely instead of just the last character d

No specific files or code needed — happens with any text in the chat input.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.169 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_