Make agent aware of dirs added with --add-dir

What version of Codex CLI is running?

0.118.0

What subscription do you have?

Plus

Which model were you using?

gpt-5.4

What platform is your computer?

macOS

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

Ghostty

What issue are you seeing?

When I start a session with codex --add-dir /path/to/dir, I have to tell codex to check the directory manually each time, and the dir isn't auto-completable which makes the experience not great.

What steps can reproduce the bug?

1. Start a session with codex --add-dir /path/to/some/other/dir
2. Ask questions about things in that dir, try to use @ to mention files there

What is the expected behavior?

@ should be able to complete files in the added dir, and agent should try to look into the added dir automatically

Additional information

_No response_