Shift+Enter - Multiline Input Does Not Work

### Describe the bug

If you write a line and press Shift+Enter with the Multiline Terminal enabled, it simply sends the text as a Prompt and not add a new line.

### Affected version

1.0.61

### Steps to reproduce the behavior

1. Write text
2. Press Shift+Enter

### Expected behavior

Add a new line below your text.

### Additional context

_No response_

Start by reproducing the issue with Multiline Terminal enabled: type text and press Shift+Enter, then inspect the terminal input handling for that key combination. Done means Shift+Enter inserts a new line instead of sending the text as a prompt, while ordinary prompt submission remains unchanged.

Scritto dal modello di indicizzazione a partire dal testo della issue.