[BUG] Numpad keys produce raw CSI u escape sequences instead of digits in iTerm2

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?

• Claude Code version: 2.1.2
• Platform: macOS (darwin)
• Terminal: iTerm2 3.6.6
• TERM: xterm-256color

## Bug Description
Numpad keys output raw Kitty keyboard protocol escape sequences instead of their digit values:

• Numpad 1 → [57400u
• Numpad 2 → [57401u
• Numpad 3 → [57402u
• etc.

What Should Happen?

Numpad keys should produce their digit values (0-9)

Error Messages/Logs

Steps to Reproduce

1. Open iTerm2
2. Launch claude
3. Press numpad number keys
4. Observe escape sequences instead of digits

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.2

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

• Works correctly in normal terminal sessions (outside Claude Code)
• Issue started appearing recently (possibly after status line update or version upgrade)