As discussed in chat, I'd like to be able to use broot as a dual pane file manager to manually sort files into a hierarchy. I keep accidentally closing one of the panels when I move in the wrong direction.

The idea we discussed was to introduce two new verbs, cycle_panel_left and cycle_panel_right (maybe focus instead of panel to make it clear that the panel itself doesn't move), that move the focus from one pane to the next without opening or closing panes.