fix(ios): guard FlutterSceneLifeCycleDelegate with compile-time check

Instead of hard-requiring Flutter >=3.38.0, wrap FlutterSceneLifeCycleDelegate
protocol adoption and addSceneDelegate with #if __has_include guards.

- Flutter >=3.38 (header present): UIScene delegate registered, all three
  scene callbacks active — deep links work under UIScene migration.
- Flutter <3.38 (header absent): guard skips it at compile time, plugin
  falls back to application:openURL: — backward compatible.

pubspec.yaml reverts flutter constraint to >=1.10.0 (no breaking change).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Kobikg78

ios/Classes/AppsflyerSdkPlugin.h

@@ -6,7 +6,11 @@
 #import "AppsFlyerLib.h"
 #endif
 
+#if __has_include(<Flutter/FlutterSceneLifeCycleDelegate.h>)
 @interface AppsflyerSdkPlugin: NSObject<FlutterPlugin, FlutterSceneLifeCycleDelegate>
+#else
+@interface AppsflyerSdkPlugin: NSObject<FlutterPlugin>
+#endif
 
 @property (readwrite, nonatomic) BOOL isManualStart;
 

ios/Classes/AppsflyerSdkPlugin.m

@@ -68,9 +68,11 @@ + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
     [registrar addMethodCallDelegate:instance channel:channel];
     [registrar addMethodCallDelegate:instance channel:callbackChannel];
     [registrar addApplicationDelegate:instance];
+#if __has_include(<Flutter/FlutterSceneLifeCycleDelegate.h>)
     if (@available(iOS 13.0, *)) {
         [registrar addSceneDelegate:instance];
     }
+#endif
 
 }
 
@@ -965,6 +967,7 @@ - (BOOL)application:(UIApplication *)application continueUserActivity:(NSUserAct
     return NO;
 }
 
+#if __has_include(<Flutter/FlutterSceneLifeCycleDelegate.h>)
 #pragma mark - FlutterSceneLifeCycleDelegate
 
 // UIScene-based URI-scheme deep links (iOS 13+, Flutter 3.41+ UIScene migration)
@@ -990,6 +993,7 @@ - (BOOL)scene:(UIScene*)scene continueUserActivity:(NSUserActivity*)userActivity
     [[AppsFlyerAttribution shared] continueUserActivity:userActivity restorationHandler:nil];
     return NO;
 }
+#endif // __has_include(<Flutter/FlutterSceneLifeCycleDelegate.h>)
 
 
 @end

pubspec.yaml

@@ -6,7 +6,7 @@ homepage: https://github.com/AppsFlyerSDK/flutter_appsflyer_sdk
 
 environment:
   sdk: '>=2.17.0 <4.0.0'
-  flutter: ">=3.38.0"
+  flutter: ">=1.10.0"
 
 dependencies:
   flutter: