[TUI] config to set `persist_extended_history` flag

What variant of Codex are you using?

CLI

What feature would you like to see?

Hi,

Thank you so much for your work, I really appreciate it.

I saw that the TUI is about to support the App Server, and I think it would be useful to add a config setting so that the TUI can enable the persist_extended_history flag. I sometimes want to go back to a thread and check the tool calls, commands execution, and file changes. I can do it when I'm spinning up and calling the App Server myself, but not when using Codex CLI directly.

I don't know if the flag is still considered experimental but would love to discuss this with you. I'd love to help!