fix(rokt): limit selectShoppableAds support to iOS

Remove the web selectShoppableAds bridge call and document platform behavior so the API remains explicitly iOS-only for now.

Made-with: Cursor

Author: denischilik

lib/mparticle_flutter_sdk.dart

@@ -333,8 +333,10 @@ class Rokt {
 
   /// Selects shoppable ads with a [identifier], optional [attributes], and optional [roktConfig].
   ///
-  /// This method currently has native implementation on iOS.
-  /// Android keeps a no-op bridge for cross-platform API compatibility.
+  /// This method is currently implemented only on iOS.
+  ///
+  /// Android keeps a no-op bridge for API compatibility, and web does not
+  /// implement this method yet.
   Future<void> selectShoppableAds({
     required String identifier,
     Map<String, dynamic>? attributes,

lib/mparticle_flutter_sdk_web.dart

@@ -536,18 +536,6 @@ class MparticleFlutterSdkWeb {
           })
         ]);
         break;
-      case 'roktSelectShoppableAds':
-        final mpRokt = JsObject.fromBrowserObject(context['mParticle']['Rokt']);
-        final placementId = call.arguments['placementId'];
-        final attributes = call.arguments['attributes'] ?? {};
-
-        mpRokt.callMethod('selectShoppableAds', [
-          JsObject.jsify({
-            'identifier': placementId,
-            'attributes': attributes
-          })
-        ]);
-        break;
       default:
         throw PlatformException(
           code: 'Unimplemented',