[BUG] shift+enter not working

Environment

• Platform (select one):
• [x] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: <!-- output of claude --version -->
• Operating System: <!-- e.g. macOS 14.3, Windows 11, Ubuntu 22.04 -->
• Terminal: <!-- e.g. iTerm2, Terminal App -->

Bug Description

<!-- A clear and concise description of the bug -->
when pressing shift+enter the prompt is sent directly, but in this textarea-like element i expect it to add a line break.

Steps to Reproduce

1. claude
2. <prompt> shift+enter

i expect to get a line break in my prompt and not send this
(iam using kitty + zsh)

Actual Behavior

its sending the prompt directly

Additional Context

<!-- Add any other context about the problem here, such as screenshots, logs, etc. -->