Korean IME (Hangul) input broken in WSL2 terminal - pre-edit text appears below input field

Environment

• OS: Windows 11 + WSL2 (Ubuntu)
• Terminal: Windows Terminal
• Claude Code version: 2.1.81
• Input method: Windows Korean IME (Microsoft IME)

Description

When typing Korean (Hangul) inside Claude Code's input field, IME pre-edit (composition) characters appear below the input field instead of inline. Characters are only committed to the input field after pressing Space.

This issue does NOT occur in a regular bash terminal — Korean input works correctly there.

Steps to reproduce

1. Open Claude Code in WSL2 terminal
2. Switch to Korean input mode (Windows Korean IME)
3. Type any Korean character

Expected behavior

Korean characters should appear inline in the input field in real-time, as they do in a regular terminal.

Actual behavior

Pre-edit characters appear below the input field. Only finalized characters (after pressing Space) appear in the correct position.

Additional notes

Rolling back to versions 2.1.80 and 2.1.79 did not resolve the issue. The problem appeared starting around March 24, 2026.