/restart exits the session instead of restarting

### Describe the bug

I've used /restart to restart the session without closing the cli, but now it just exits like /exit.

### Affected version

GitHub Copilot CLI 1.0.14

### Steps to reproduce the behavior

Start a session, send some messages, wait for response, then send /restart.

### Expected behavior

The cli restarts inline without exiting.

### Additional context

_No response_

Start by tracing the CLI command handling for /restart and compare it with /exit. Reproduce the behavior in GitHub Copilot CLI 1.0.14, then verify that /restart keeps the session open and restarts inline rather than exiting.

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