[BUG] Shift+Enter no longer inserts newline over SSH (v2.1.70)

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?

Shift+Enter no longer inserts a newline in the chat input when connected over SSH. It was working correctly in 2.1.69. The help screen (?) still shows "shift + ⏎ for newline" but nothing happens when pressing it.

This is likely a regression from the 2.1.70 fix: "Fixed Enter inserting a newline instead of submitting when typing over a slow SSH connection". In 2.1.69, Shift+Enter over SSH was explicitly fixed (changelog: "Fixed Shift+Enter printing [27;2;13~ instead of inserting a newline in Ghostty over SSH").

What Should Happen?

Pressing Shift+Enter should insert a newline in the chat input, as documented in the help screen and as it worked in 2.1.69.

Error Messages/Logs

No error message. Shift+Enter is silently ignored — no newline inserted, no visible feedback.

Steps to Reproduce

1. SSH into a remote Linux server (Ubuntu 22.04, default bash)
2. Run claude (version 2.1.70)
3. Type some text in the chat input
4. Press Shift+Enter
5. Nothing happens — no newline is inserted
6. Downgrading to 2.1.69 restores the expected behavior

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.70

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_