[BUG] iTerm2 keybinding for shift+enter breaks shift+enter in other programs running in iTerm2

Environment

• Platform (select one):
• [x] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other:
• Claude CLI version: 0.2.53 (Claude Code)
• Operating System: macOS 15.3.2
• Terminal: iTerm2 3.5.11

Bug Description

The terminal setup command, which installs a keybinding for Shift+Enter in iTerm2 config breaks Shift+Enter in other terminal programs, such Neovim, yazi, helix editor.

Claude Code runs the following command to install the Shift+Enter keybinding:

defaults write com.googlecode.iterm2 GlobalKeyMap -dict-add 0xd-0x20000-0x24 '<dict><key>Text</key><string>\\n</string><key>Action</key><integer>12</integer><key>Version</key><integer>1</integer><key>Keycode</key><integer>13</integer><key>Modifiers</key><integer>131072</integer></dict>'

Steps to Reproduce

Reproduce with Neovim:

1. perform terminal setup via claude, or run the above setup command directly
2. launch nvim
3. press : to enter command mode
4. type imap <S-Enter> hello and press enter
5. press i to enter insert mode
6. press shift+enter
7. notice a new line is added, while "hello" should have been inserted into the buffer
8. remove the iTerm2 keybinding (Settings -> Keys -> Key Bindings)
9. press shift+enter
10. notice "hello" is inserted into the buffer

Reproduce with Yazi:

1. perform terminal setup via claude, or run the above setup command directly
2. launch yazi
3. select a file by pressing space
4. press shift+enter (this keybinding is a default one, documented here https://yazi-rs.github.io/docs/quick-start)
5. notice the file is opened immediately in a default associated program ($EDITOR)
6. remove the iTerm2 keybinding (Settings -> Keys -> Key Bindings)
7. press shift+enter
8. notice yazi displays "Open with" popup, as expected

Expected Behavior

Claude Code's terminal setup doesn't break Shift+Enter behavior in other terminal programs.

Actual Behavior

Claude Code's terminal setup breaks Shift+Enter behavior in other terminal programs.

Additional Context

Neovim, Yazi, and increasing number of CLI programs use Kitty keyboard protocol for advanced keyboard shortcuts. By mapping Shift+Enter to "\n" (what you do here) you're preventing actual Shift+Enter sequence (kitty protocol encoded) from hitting any program running in iTerm2. I strongly suggest using a different approach for claude under iTerm2.