[Regression] gpt-oss no longer has access to apply_patch

What version of Codex CLI is running?

0.101.0

What subscription do you have?

Business

Which model were you using?

gpt-oss-120b

What platform is your computer?

Archlinux

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

Gnome Console

What issue are you seeing?

In the following commit: https://github.com/openai/codex/commit/a1abd53b6aa57f793e3552d66219e171a5f0f8c5

The code to add the apply_patch tool when using gpt-oss was removed:

} else if slug.starts_with("gpt-oss") || slug.starts_with("openai/gpt-oss") {
        model_info!(
            slug,
            apply_patch_tool_type: Some(ApplyPatchToolType::Function),
            context_window: Some(96_000),
        )

This leaves the gpt-oss models without any tool to edit, making them close to useless.

What steps can reproduce the bug?

1. Start Codex with gpt-oss
2. Ask the model to edit a random file

What is the expected behavior?

1. The model will use apply_patch to apply edits

Actual outcome:

1. The model will try to use workarounds, such as editing with sed

Additional information

Either the behavior before this commit must be reintroduced, but a cleaner fix would probably be to make this configurable, as hardcoded values for gpt-oss models is a lot less maintainable. Right now, we can actually already do the following in the configuration .toml:

[features]
apply_patch_freeform = true

Which will give the model access to the freeform version of apply_patch. Since gpt-oss expects the json version, this does not work (well). Ideally a new configuration option is introduced to give a model access to the json/function version of apply_patch.

Note: I am more than happy to write a PR to introduce such a configuration option. Kindly let me know if such a approach would be accepted, since I'd hate for me to write a pull request only for it to be rejected. If a different approach is preferred, kindly let me know and I will try to implement such an alternatively approach in a PR.