Not sure if this satisfies your requirements, but I've gotten Claude Code to run commands in tmux and view their output (including debugging my NeoVim config), so I think that a TUI is at least accessible, even though it would likely bloat the context window far more than a simple CLI.

Yeah, this is my main way of using Claude Code for anything complex – a REPL or bash window in tmux, and with Claude running commands there. That lets me easily browse through anything that's happened in a UI I'm used to, or manually intervene if needed.

That's pretty nice! It's just the context window problem, yes, but the tmux tip is pretty good nonetheless.