fix: address Copilot review on PR #487

- iOS: use setPushNotificationsDeviceTokenString for the String token
  overload (setPushNotificationsDeviceToken takes Data and would fail to
  compile), matching the documented Dart->iOS mapping.
- Dart: add the currency parameter to logSpentCredits so the dartdoc
  [currency] reference resolves and the ROAS event mirrors logDonate;
  cover it in the existing test.

https://claude.ai/code/session_011RbXF3u6F2j1NmjJ5jhUkN

Author: claude

ios/facebook_app_events/Sources/facebook_app_events/FacebookAppEventsPlugin.swift

@@ -326,7 +326,7 @@ public class FacebookAppEventsPlugin: NSObject, FlutterPlugin {
             result(FlutterError(code: "INVALID_ARGUMENT", message: "Push notification token is required", details: nil))
             return
         }
-        AppEvents.shared.setPushNotificationsDeviceToken(token)
+        AppEvents.shared.setPushNotificationsDeviceTokenString(token)
         result(nil)
     }
 

lib/src/standard_events.dart

@@ -76,6 +76,7 @@ extension StandardEventLogging on FacebookAppEvents {
   /// [valueToSum] (the credits value) and [currency].
   Future<void> logSpentCredits({
     double? valueToSum,
+    String? currency,
     String? contentType,
     String? contentId,
     Map<String, dynamic>? parameters,
@@ -85,6 +86,7 @@ extension StandardEventLogging on FacebookAppEvents {
       valueToSum: valueToSum,
       parameters: {
         if (parameters != null) ...parameters,
+        if (currency != null) FacebookAppEvents.paramNameCurrency: currency,
         if (contentType != null)
           FacebookAppEvents.paramNameContentType: contentType,
         if (contentId != null) FacebookAppEvents.paramNameContentId: contentId,

test/facebook_app_events_test.dart

@@ -739,6 +739,7 @@ void main() {
     test('logSpentCredits forwards valueToSum and content', () async {
       await facebookAppEvents.logSpentCredits(
         valueToSum: 100.0,
+        currency: 'USD',
         contentType: 'coins',
         contentId: 'pack-1',
       );
@@ -750,6 +751,7 @@ void main() {
           arguments: <String, dynamic>{
             'name': 'fb_mobile_spent_credits',
             'parameters': <String, dynamic>{
+              'fb_currency': 'USD',
               'fb_content_type': 'coins',
               'fb_content_id': 'pack-1',
             },