copilot-cli doesn't sense that the child process that it has started is killed, doesn't tell this to the user

### Describe the bug

The make process that copilot-cli was running was stuck due to it showing the dialog box and I killed make.

copilot-cli didn't sense this and kept waiting, checking on it.

Then copilot quietly restarted the same process without telling the user.

See the comments on the screenshot.

copilot should tell the user that the child process exited with the signal.
This is important, and the user doesn't get notified.

Version: 0.0.337
FreeBSD 14.3

### Affected version

_No response_

### Steps to reproduce the behavior

_No response_

### Expected behavior

_No response_

### Additional context

_No response_