Esc dismissing skills autocomplete interrupts running task

Summary

Pressing Esc to dismiss the skills autocomplete popup also interrupts the currently running task.

Steps to Reproduce

1. Start a Codex task and wait for it to be running/thinking.
2. While it is running, type $ to open the skills dropdown.
3. Press Esc to dismiss the dropdown.

Expected

Only the dropdown is dismissed; the task continues.

Actual

The task is interrupted/cancelled.

Notes

• Observed with multi-line prompts too, but reproduces with a single line.

Proposed fix

Ensure Esc only sends interrupt when no composer popup is active; add a regression test in codex-rs/tui.