Add iOS 26 fluid zoom transition for Menu sheets

On iOS 26+, Menu bottom sheets now morph from their trigger button
using UIViewController.preferredTransition = .zoom. This creates a
fluid visual connection between the trigger and the presented sheet,
complementing the Liquid Glass design language.

The sourceViewTag prop is also available on the generic Dialog/BottomSheet
layer so any dialog can opt into the zoom transition.

https://claude.ai/code/session_011cNDhEb2cDgg5QbVuzEyH1

modules/bottom-sheet/ios/BottomSheetModule.swift

@@ -42,6 +42,10 @@ public class BottomSheetModule: Module {
       Prop("preventExpansion") { (view: SheetView, prop: Bool) in
         view.preventExpansion = prop
       }
+
+      Prop("sourceViewTag") { (view: SheetView, prop: Int?) in
+        view.sourceViewTag = prop
+      }
     }
   }
 }