[BUG] Pressing Enter to confirm IME (Japanese) conversion unintentionally sends the prompt

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When typing in Japanese (using an IME) in the VS Code extension's chat input field, pressing the Enter key to confirm a character conversion sends the prompt prematurely. This occurs even when I am in the middle of composing a sentence, making it extremely difficult to type complex questions that require multiple text conversions.

What Should Happen?

The Enter key should not send the prompt when the Input Method Editor (IME) is active for text composition. Its only function should be to confirm the selected characters (e.g., finalizing a Kanji conversion). Sending the prompt should be a distinct action performed only after the user has finished typing.

Error Messages/Logs

No specific error messages or logs are generated. This is a UI behavioral issue.

Steps to Reproduce

1. Open the Claude Code extension on Mac and show the chat panel in VS Code.
2. Focus on the chat input field.
3. Switch the PC's input method to Japanese (turn on IME).
4. Type a Japanese phrase that requires conversion, for example, "kakuchoukinou".
5. As the IME suggests conversion candidates (e.g., 「拡張機能」), press the Enter key to confirm the selection.
6. The prompt is immediately sent with only the confirmed text ("拡張機能"), even though the intention was to continue typing the rest of the sentence.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.0

Platform

Other

Operating System

macOS

Terminal/Shell

Other

Additional Information

This issue occurs within the VS Code GUI (the chat input box) and is not dependent on a specific terminal or shell. This issue likely affects users of many languages that rely on an Input Method Editor (IME) where the Enter key is used for text composition, such as Chinese and Korean. This behavior significantly degrades the user experience and usability of the extension for speakers of these languages.