Thai combining characters not rendering correctly during input

Description

When typing Thai text in the Claude Code chat input, combining characters (vowels that appear above/below consonants such as สระอิ อี อุ อู and tone marks) disappear or render incorrectly during typing. Once Enter is pressed, the text is sent correctly and displayed properly in the conversation.

Steps to Reproduce

1. Open Claude Code in any terminal on Windows
2. Type any Thai text that contains combining characters (e.g. สระ อี อิ)
3. Observe that vowels/tone marks above or below consonants disappear or misalign during input

Expected Behavior

Thai combining characters should display correctly while typing, matching the final submitted text.

Actual Behavior

Combining characters (สระบน/ล่าง, วรรณยุกต์) disappear or show incorrectly during input. The text is only displayed correctly after pressing Enter.

Environment

• OS: Windows 11 Pro
• Terminal: Windows Terminal (also reproducible in other terminals)
• Shell: Bash

Notes

This appears to be an issue with the input rendering library used by Claude Code, which does not properly handle Unicode Thai combining characters (U+0E00–U+0E7F) in real-time input display. The submitted string is always correct — only the visual rendering during typing is affected.