Selection list widget.
Displays a list of options, allows arrow/vim key navigation,
and emits on_change/on_select messages to the parent via _pending.
Props (mount-time only)
:options— list of option strings or maps%{name: "", description: nil, value: nil}:selected— currently selected index (default 0):on_change— message tag sent as{tag, selected_index}on navigation:on_select— message tag sent as{tag, selected_index, option}on Enter:id— element id (required for focus):visible_count— visible rows (default: option count):wrap_selection— wrap at bounds (default: false):fast_scroll_step— Shift+Up/Down step size (default: 5):show_description— show option descriptions (default: false):show_scroll_indicator— show scroll indicator (default: false):item_spacing— blank lines between items (default: 0)