chore: simplify loading of Mac-specific logic in config_loader

[bolinfest]

Over in config_loader/macos.rs, we were doing this complicated mod thing to expose one version of load_managed_admin_config_layer() for Mac:

codex/codex-rs/core/src/config_loader/macos.rs

Lines 4 to 5 in 580c59a

	#[cfg(target_os = "macos")]
	mod native {

While exposing a trivial implementation for non-Mac:

codex/codex-rs/core/src/config_loader/macos.rs

Lines 110 to 117 in 580c59a

	#[cfg(target_os = "macos")]
	pub(crate) use native::load_managed_admin_config_layer;
	#[cfg(not(target_os = "macos"))]
	pub(crate) async fn load_managed_admin_config_layer(
	_override_base64: Option<&str>,
	) -> io::Result<Option<TomlValue>> {
	Ok(None)

That was being used like this:

codex/codex-rs/core/src/config_loader/layer_io.rs

Lines 47 to 48 in 580c59a

	#[cfg(not(target_os = "macos"))]
	let managed_preferences = load_managed_admin_config_layer(None).await?;

This PR simplifies that callsite in layer_io.rs to just be:

    #[cfg(not(target_os = "macos"))]
    let managed_preferences = None;

And updates config_loader/mod.rs so we only pull in macos.rs on Mac:

#[cfg(target_os = "macos")]
mod macos;

This simplifies macos.rs considerably, though it looks like a big change because everything gets unindented and reformatted because we can drop the whole mod native thing now.

---

Stack created with Sapling. Best reviewed with ReviewStack.

• feat: migrate to new constraint-based loading strategy #8251
• chore: prefer AsRef<Path> to &Path #8249
• -> chore: simplify loading of Mac-specific logic in config_loader #8248

[jif-oai]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Another round soon, please!

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".