Windows: IME (CJK input) does not work in background session viewer chat input

Summary

When viewing a background (fleet) job via the Claude Code background session viewer on Windows, the chat input field does not accept IME input. Japanese (and presumably other CJK) characters cannot be composed — the IME candidate window either does not appear or input is not committed, forcing users to type in romaji/phonetic transliteration.

Environment

• OS: Windows 11 Enterprise 10.0.26200
• Claude Code: 2.1.205
• Terminal: Windows Terminal
• Language: Japanese (IME: Microsoft IME)

Steps to reproduce

1. Start a background (fleet) job from Claude Code
2. Open the background session viewer
3. Attempt to type Japanese using IME in the chat input field
4. Observe: IME does not activate / characters are not converted to Japanese

Expected behavior

IME input works in the background session viewer chat input, consistent with behavior in a normal Claude Code session window.

Workaround

Copy-paste Japanese text from an external editor (e.g. Notepad) into the input field.

Notes

This does not affect the main Claude Code session window — IME works normally there. The issue is specific to the background session viewer input.