Changes: - Default model and docs now use gpt-5-codex. - Disables the GPT-5 Codex NUX by default. - Keeps presets available for API key users.
codex-common
This crate is designed for utilities that need to be shared across other crates in the workspace, but should not go in core.
For narrow utility features, the pattern is to add introduce a new feature under [features] in Cargo.toml and then gate it with #[cfg] in lib.rs, as appropriate.