NavigationBarTileSchema
Renders a Material 3 NavigationBar with one NavigationBarItem per entry in items. An item is selected when its NavigationBarItem.id equals selectedItemId; the selected item's icon is drawn in its filled variant, the others outlined. NavigationBarItem.label is rendered centered under the icon, or omitted when null.
Selection: tapping an item dispatches a local NavigationBarTileEvents.OnItemClicked and the holder stores the new selectedItemId, so the highlight moves immediately without a server round trip. Tapping the already selected item still fires everything again.
Triggers dispatched:
OnNavigationBarItemClickEventTrigger— fired when an item is tapped, carrying that item's NavigationBarItem.id, so events can be wired per item.
Notes: the bar itself is not clickable and fires no display trigger. It only tracks the selected item — performing the actual navigation is up to the events wired to the item clicks.