Numpad keys output escape sequences instead of numbers in iTerm2 (v2.1.5)

Environment

• Claude Code version: v2.1.5 (latest)
• Terminal: iTerm2
• OS: macOS (Darwin 24.6.0)

Problem

After upgrading to the latest version (v2.1.5), numpad keys output escape sequences instead of actual numbers:

[57399u [57400u [57401u [57402u

This is a regression - it worked correctly in previous versions.

Steps to Reproduce

1. Open iTerm2
2. Start claude
3. Press any numpad key (0-9)

Expected Behavior

Should display the corresponding digit (0-9)

Actual Behavior

Displays CSI u escape sequences like [57399u, [57400u, etc.

Attempted Fixes (none worked)

• Disabling "Report modifiers using CSI u" in iTerm2 preferences
• Setting TERM=xterm-256color before launching claude

Notes

• Main keyboard number keys work correctly
• Issue appeared immediately after upgrading to v2.1.5
• This appears to be related to Kitty keyboard protocol / CSI u mode handling