Add confirmation or double-press behavior for Ctrl+C interrupt in Codex CLI

Codex CLI currently stops the active response or task immediately when Ctrl+C is pressed.

This is easy to trigger by mistake, especially when the user intended to paste text or interact with the terminal and accidentally presses Ctrl+C instead. In long-running responses or coding tasks, this can interrupt useful work unintentionally.

It would be helpful if Codex CLI supported a safer interrupt behavior, such as:

• Press Ctrl+C once: show a warning
• Press Ctrl+C again within a short time window: actually stop the current response/task

Example message:

Press Ctrl+C again to stop Codex.

Alternatively, Codex CLI could ask for confirmation:

Stop current Codex response? [y/N]

Ideally this behavior would be configurable, so users who prefer the current immediate interrupt behavior can keep it.

Possible config example:

[interaction]
confirm_interrupt = true
interrupt_mode = "double-ctrl-c"

This would reduce accidental interruptions while preserving a fast way to stop Codex when needed.