Tab completion after `!` shell prefix in Codex CLI

What version of Codex is running?

0.88.0

What subscription do you have?

Plus

Which model were you using?

gpt-5.2-codex

What platform is your computer?

Darwin 25.2.0 arm64 arm

What terminal emulator and version are you using (if applicable)?

Ghostty (zsh, ohmyzsh, starship)

What issue are you seeing?

No tab completion after ! shell prefix in Codex CLI

What steps can reproduce the bug?

1. Start Codex CLI interactive session.
2. Type !cat R and press <TAB>.

What is the expected behavior?

Shell-style completion for files/commands (e.g., expands to !cat README.md).

Additional information

Expected:
Shell-style completion for files/commands (e.g., expands to !cat README.md).

Actual:
<TAB> does nothing; no completion is triggered in ! mode.