type NativeGlassHeaderItem = {  readonly type: "button" | "menu";  readonly glassEffect?: boolean;  readonly hidesSharedBackground?: boolean;  readonly sharesBackground?: boolean;  readonly variant?: "plain" | "done" | "prominent";  readonly width?: number;}; /** * iOS 26/27 Mail-style header controls need the native glass button * shared background configuration when they are not part of a larger toolbar. * Do not enable `glassEffect` for normal bar-button items: react-native-screens * renders that as a custom UIButton, which creates a second skinny capsule. */export function withNativeGlassHeaderItem<T extends NativeGlassHeaderItem>(  item: T,  options: {    readonly hidesSharedBackground?: boolean;    readonly sharesBackground?: boolean;    readonly width?: number;  } = {},): T {  const sharesBackground = options.sharesBackground ?? item.sharesBackground ?? true;  return {    ...item,    glassEffect: item.glassEffect ?? false,    hidesSharedBackground: options.hidesSharedBackground ?? item.hidesSharedBackground ?? false,    sharesBackground,    variant: item.variant ?? "plain",    width: options.width ?? item.width,  } as T;}