Adapt SwiftUI and UIKit navigation bars, toolbars, tab bars, sheets, custom controls, and overflow menus for the vertical bar on iPhone Duo without losing essential actions or labels. Use when bars do not move to the side, items disappear or overflow, text-only or custom-view items stay horizontal, a screen should keep horizontal bars, or you need axisBehavior, visibilityPriority, toolbarVerticalEdge or verticalBarEdge, toolbarVerticalBehavior or preferredVerticalBarBehavior, or vertical bar compression.
