C:/Program Files/Git/config model command writes ANSI escape codes into settings.json

Bug Description

The /config command (or /model) writes ANSI terminal formatting escape sequences into settings.json instead of the clean model identifier.

Steps to Reproduce

1. Open Claude Code on Windows (Git Bash shell)
2. Run /config and select a model (e.g., Opus)
3. Check ~/.claude/settings.json

Expected Behavior

{
  "model": "claude-opus-4-6"
}

Actual Behavior

The terminal output already shows the escaped formatting:

Set model to [1mopus[1m] (claude-opus-4-6[1m])[22m

And settings.json contains the ANSI bold marker in the value:

{
  "model": "opus[1m]"
}

[1m is the ANSI escape code for bold text. It appears the display formatting is leaking into the persisted value.

Impact

Claude Code silently uses the default model instead of the configured one, since opus[1m] is not a valid model identifier. The user has no indication that the setting is broken until they manually inspect settings.json.

Environment

• OS: Windows 11 Pro (10.0.26200)
• Shell: Git Bash (mintty/MSYS2)
• Claude Code: Latest (installed via npm)