Light mode auto-detection not working with Ghostty terminal

[gavmor]

Description

Crush doesn't auto-detect my Ghostty terminal's light theme and renders UI with dark colors, making it hard to read on a light background.

Environment

• Terminal: Ghostty
• Terminal theme: Light
• OS: macOS
• Crush version: v0.53.0
• $TERM: xterm-ghostty
• $COLORTERM: truecolor

Terminal background color

When queried, the terminal reports:

11;rgb:fbfb/f1f1/c7c7

This is a very light cream/yellow color.

Steps to reproduce

1. Set Ghostty to a light theme
2. Run crush
3. UI renders with dark colors

Expected behavior

Crush should auto-detect the light background and render text/UI in light-appropriate colors (dark text on light background).

Additional context

• Other terminal applications correctly detect and render in light mode
• Debug logs show no color profile detection messages
• Ghostty is properly reporting its background color via terminal escape sequences