launchig `$mcat` in a directorie containing lot of subfolders and file use to crash the terminal

[JE-Amouel]

Hi,
when i do $mcat being at the root of a very vast directories take time to show or hider make my terminal crash.
my humble suggestion is to add collapsible sub-directories, so the command will not try to list all files before displaying the selection menu,
by default it can start with collapsed sub-directories

[Skardyy]

for now the TUI for multi-select is kinda limiting. I don't really have a way to redraw it, so it will require rethinking it.

won't be a quick fix