feat(mobile): thread header minimizes on the Duo while reading back through history#24235

@@ -279,6 +282,11 @@ export function V5StackHeader(props: {
       backButtonHidden={options.headerBackVisible === false}
       ios={{
         navigationItemStyle: options.unstable_navigationItemStyle,
+        // Only the Duo's short display needs the room. Its system default hides the bar on
+        // every registered scroll view, so screens that don't opt in keep it fixed.
+        minimizationBehavior: isDuoDevice(deviceType)
+          ? (options.unstable_headerMinimizationBehavior ?? "never")
+          : undefined,