Unable to terminate via SIGTERM (CTRL+C) when using `-p`

[nsgundy]

Describe the bug

When executing a prompt passed via -p, copilot-cli won't terminate when its being sent SIGTERM / CTRL+C, making it difficult to terminate copilot-cli in scripted workflows.

Affected version

0.0.398

Steps to reproduce the behavior

1. Execute copilot-cli prompt using -p

copilot --model gpt-5-mini -p "test"

2. Press CTRL+C before the above returns

Expected behavior

Expecting copilot-cli to terminate immediately when receiving SIGTERM / CTRL+C.

Additional context

Ran inside a Docker development container based on Ubuntu 20.04.