Add tabViewBottomAccessory to native tabs

[hennessyevan]

Now that native tabs have landed, how difficult would it be to support tabViewBottomAccessory?

This is a new API in iOS26+ that allows showing a view that floats above the iOS tabbar. Additionally, it allows adapting the view to fit when the tabbar is minimized.

Ideally in the react native screens API this would look like

<Tabs tabViewBottomAccessory={MyAccessoryView}>...</Tabs>

function MyAccessoryView() {
  const placement = useTabViewBottomAccessoryPlacement()

  return (
    <View styles={{ backgroundColor: placement === 'inline' ? 'red' : 'green' }} />
  )
}

[kkafar]

Hey! We plan on landing that. This is just a matter of it getting to the top of the task list. We're currently heavily focused on iOS 26 support & stabilisation. Once that is done, new features for new APIs will be on the plate.