Feature request: First-class background job management in Codex CLI

What feature would you like to see?

Codex CLI can spawn long-running commands (e.g. crawlers, browsers, build tasks, or local dev servers).
Currently, if a session is interrupted, these commands may continue running in the background with no visibility or control.

This feature request proposes making background execution explicit and manageable, rather than implicit and invisible.
These processes are often intentionally long-lived, which makes silent background execution particularly dangerous when users believe the task has been stopped.

Additional information

_No response_