window list display

[Per Bothner]

Create a UI for displaying and selecting from a list of windows. Similar to the display status output, but dynamically updated, and selectable. Sub-windows should be grouped by top-level window, and otherwise (by default) ordered by window-number. Detached sessions are listed as if belonging to a pseudo-window at the end.

As window state changes, the display is updated on-the-fly by messages from the server.

Should allow selecting multiple windows. Selected windows should be indicated by "selection colors", typically white-on-blue.

Should be available as either a popup (short-term) or an actual window/pane.
Enter will focus/activate the selected window (or one of them if multiple windows are selected).
Esc will exit and focus the "old" window (the one that was focused before the window-list was focused).
In popup mode, Enter or Esc will remove the popup.

Key-bindings similar to navigating menus or file browsers. Primary navigation is with mouse or up/down-arrow. Multi-select like Gnome Files or KDE Dolphin or macOS Finder.

Can use a window specifier list to initialize/change selected window(s). This can be entered either via a domterm sub-command or a popup text entry field.

Selected windows should have some indicator/feedback in the actual windows, not just in the window list display.

A context menu will allow various operations, including: close; detach; create new top-level window and move all selected window to be a tab in the new window; move each selected window to a separate top-level window; move next foucused window; copy selection (in the format of a window specifier list) to the clipboard. "Moving" a detached session attaches it to a new window/pane.