Document project-scoped terminal pet selection with [tui].pet

What is the type of issue?

Documentation is missing

What is the issue?

Codex supports project-scoped terminal pet selection, but the current documentation only describes choosing a terminal pet through /pets, and the configuration reference does not list tui.pet.

This makes pet selection appear user-global, especially because the /pets picker persists its selection to the user configuration.

On codex-cli 0.146.0, I verified that a project configuration can override the user-selected pet:

# <project>/.codex/config.toml
[tui]
pet = "custom:my-project-pet"

A config/read request resolved the project pet as the effective value and attributed tui.pet to the project .codex layer.

Please document:

• tui.pet in the configuration reference;
• the required identifier format for built-in and custom pets;
• that it may be placed in a trusted project’s .codex/config.toml;
• that /pets writes the user-level selection rather than the project override.

Where did you find it?

• https://developers.openai.com/codex/pets
• https://developers.openai.com/codex/config-reference
• https://developers.openai.com/codex/config-basic