Cmux Debug Windows

This gives Claude direct control over cmux's window and pane topology: creating splits, moving surfaces between panes, focusing specific terminals, and triggering visual flash cues for attention. It's the foundation for any cmux automation that needs deterministic placement instead of hoping things land in the right spot. The handle model (window:N, pane:N, surface:N) makes it easy to script repeatable layouts. One thing worth noting: cmux settings live in their own JSON file separate from Ghostty's terminal config, and you can reload both without restarting the app. If you're building workflows that juggle multiple terminal sessions or need to programmatically arrange panes, this is where you start.