[Feature Request] Make Enter key behavior configurable in Chat input for IME compatibility

Bug Description

Feature Request: Make Enter key behavior configurable in Chat input
This is an EXTREAMLY IMPORTANT feature for Japanese (Chinese too, maybe).

Problem:
In Claude Code's Chat input, Enter is hardcoded to chat:submit at a lower layer than keybindings.json. Setting "enter": "chat:newline" or "enter": null in keybindings.json completely breaks submit — neither physical Ctrl+J nor any other key can submit afterward.

Impact:
Japanese IME users on Mac are especially affected. IME commit (変換確定) fires Enter, which immediately submits the chat — unintended and disruptive.

What I tried (all failed):

• Ghostty: keybind = enter=text:\n → breaks IME
• CC: "enter": "chat:newline" + "meta+enter": "chat:submit" → meta+enter doesn't fire
• CC: "enter": null + "meta+enter": "chat:submit" → null doesn't suppress the hardcoded CR submit
• CC: "enter": "chat:newline" + "ctrl+j": "chat:submit" → ctrl+j also stops working

Request:
Please, please make Enter key behavior configurable via keybindings.json, similar to how Cursor allows toggling Enter between newline and submit in Settings. thank you.

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.112
• Feedback ID: 350b497d-dd56-4baf-9595-b5a9626011a9

Errors

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