`claude attach` repaint joins lines containing a skin-tone emoji

Claude Code 2.1.284 · Windows 11 (26200) · Windows Terminal 1.24

Steps

1. claude --bg -n test, then run the claude attach … it prints.
2. Send: Write one plain paragraph of about 600 characters about a family trip, using a skin-tone thumbs-up, the Romanian flag and a family emoji several times each. No tools.
3. The answer draws correctly. Press Ctrl+Z, then run claude attach … again.

Actual: the repainted transcript is garbled: lines joined, text pushed to the right edge, prompt and status line misplaced. Running claude directly is clean.

Cause, from captured output: a line holding a skin-tone thumbs-up (👍🏽, U+1F44D U+1F3FD) is written live as …That evening \r\n the whole…, but the re-attach repaint writes …That evening the whole…, with spaces instead of the line break.