[BUG] File picker selection highlight not visible with macOS system /bin/zsh (ncurses 5.4 issue)

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?

When using the @ file picker in Claude Code, the selection highlight is not visible when running under macOS system /bin/zsh. Files appear as blue underlined links, but there's no visual indication of which item is currently selected when navigating with arrow keys.

Environment

• Claude Code version: 2.0.75
• OS: macOS 15 (darwin25.0)
• Terminal: GoLand integrated terminal
• Shell: /bin/zsh (zsh 5.9, arm64-apple-darwin25.0)

Root Cause

The system /bin/zsh links against /usr/lib/libncurses.5.4.dylib, while Homebrew zsh links against /opt/homebrew/opt/ncurses/lib/libncursesw.6.dylib.

The older ncurses 5.4 lacks proper terminal UI rendering for the file picker selection highlight.

otool -L /bin/zsh
/usr/lib/libncurses.5.4.dylib <-- old, no wide char support

otool -L /opt/homebrew/bin/zsh
/opt/homebrew/opt/ncurses/lib/libncursesw.6.dylib <-- newer, wide char support

Steps to Reproduce

1. Use macOS system /bin/zsh as your shell
2. Run Claude Code
3. Type @ followed by a pattern (e.g., @.go)
4. Try to navigate the file list with arrow keys
5. Notice no selection highlight is visible

What Should Happen?

Expected Behavior

A visible highlight showing which file is currently selected.

Actual Behavior

No highlight visible. All items appear as static blue underlined text.

Error Messages/Logs

Steps to Reproduce

1. Use macOS system and goland terminal /bin/zsh as your shell
2. Run Claude Code
3. Type @ followed by a pattern (e.g., @.go)
4. Try to navigate the file list with arrow keys
5. Notice no selection highlight is visible

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.75

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

_No response_