OptionalautoOptionalfocusDefault true. Ignored when focusId is set — focus state then comes
from the useFocus registration instead.
OptionalfocusRegister this MultiSelect with useFocus(id) so the surrounding
<FocusProvider> can route Tab / Shift+Tab cycling through it.
OptionalindicatorCustom marker rendered to the left of each row's label.
OptionalinitialDefault 0; clamped forward to first non-disabled item.
Called when the user toggles an item via Space. Receives a NEW Set containing the resulting selection.
OptionalonFires whenever the highlight cursor moves (skips initial mount).
OptionalonCalled when the user presses Enter. Receives the items currently in
selectedKeys, ordered to match items.
Currently-selected items, keyed by item.key ?? String(item.value).
Controlled — onChange produces the next Set.
When
focusIdis set, take focus on mount if no other focusable currently holds it.