Move URL validation to StripePlugin

Author: meylis1998

packages/stripe_ios/ios/stripe_ios/Sources/stripe_ios/Stripe Sdk/StripeSdkImpl.swift

@@ -391,15 +391,16 @@ public class StripeSdkImpl: NSObject, UIAdaptivePresentationControllerDelegate {
         resolve(false)
         return;
       }
-      guard let urlObj = URL(string: url) else {
+      let urlObj = URL(string: url)
+      if (urlObj == nil) {
         #if DEBUG
         print("[flutter_stripe] handleURLCallback called with invalid URL: \(url)")
         #endif
         resolve(false)
         return
       }
       DispatchQueue.main.async {
-        let stripeHandled = StripeAPI.handleURLCallback(with: urlObj)
+        let stripeHandled = StripeAPI.handleURLCallback(with: urlObj!)
         #if DEBUG
         if stripeHandled {
           print("[flutter_stripe] URL callback successfully handled by Stripe SDK: \(url)")

packages/stripe_ios/ios/stripe_ios/Sources/stripe_ios/StripePlugin.swift

@@ -501,6 +501,16 @@ extension  StripePlugin {
             result(FlutterError.init(code: ErrorType.Failed, message: "Invalid parametes", details: nil))
             return
         }
+
+        // Validate URL format before passing to StripeSdkImpl
+        guard URL(string: url) != nil else {
+            #if DEBUG
+            print("[flutter_stripe] handleURLCallback called with invalid URL: \(url)")
+            #endif
+            result(false)
+            return
+        }
+
         handleURLCallback(
             url: url,
             resolver: resolver(for: result),