Korean IME: composing character still moves to wrong position on arrow key press (v1.24.11321.0)

Description

When composing a Korean (Hangul) character and pressing an arrow key before the composition is finalized, the composing character is inserted at the new cursor position instead of staying at the original position.

This was reportedly fixed in #20039 and #20041, but the issue still reproduces on v1.24.11321.0 (stable).

Steps to reproduce

1. Open Windows Terminal (any shell: cmd, PowerShell, or WSL bash)
2. Type Korean text, e.g. 가나 and begin composing the next character (e.g. ㄷ)
3. Before finalizing the composition (without pressing Space/Enter), press an arrow key (← or →)
4. The composing character (ㄷ) moves to the cursor's new position

Expected behavior

The composing character should be finalized at its original position before the cursor moves.

Actual behavior

The composing character follows the cursor and is inserted at the wrong position.

Environment

• Windows Terminal: v1.24.11321.0 (stable)
• Windows: 23H2
• Shells tested: cmd, PowerShell 5.1, WSL2 bash
• Microsoft IME (legacy mode)
• conhost.exe does NOT have this issue — only Windows Terminal