Shift+Enter no longer creates a new line in the input

Bug Description

Shift+Enter no longer inserts a new line in the CLI input. Previously this worked as expected — pressing Shift+Enter would move the cursor to a new line within the input field, allowing multi-line input before submitting.

Expected Behavior

Shift+Enter should insert a newline character in the input, just like it did before.

Actual Behavior

Pressing Shift+Enter does not create a new line.

Environment

• Claude Code version: 2.1.70
• OS: macOS (Darwin 25.3.0)
• Shell: zsh