Statusline blank when output contains ANSI color codes

Environment

• Claude Code 2.1.19
• macOS (Darwin 25.2.0)
• Ghostty 1.2.3 (TERM=xterm-ghostty, COLORTERM=truecolor)

Description

Custom statusline scripts that output ANSI color escape codes result in a completely blank statusline. Plain text output works fine.

Repro

1. Set statusline to: echo "TEST" → works, shows "TEST"
2. Set statusline to: printf '\e[32mTEST\e[0m' → blank, nothing displayed

Expected

Colored text displays in statusline

Actual

Statusline is empty

This was working ~1 week ago. Possibly a regression in 2.1.x.