Add `/clear` command to clear current screen in addition to creating a new context

What feature would you like to see?

Claude and Gemini both have a /clear command that cleans the terminal back to when you first open these tools and clears also the context. I know Codex has /new but that not only is not very intuitive for existing terminal users but also doesn't clear the screen and is different from the other tools.

Additional information

_No response_