fix: Enforce correct type for purchase vs subscription requests

- requestPurchaseWithSku now always uses .inApp type
- Added requestSubscriptionWithSku for subscription purchases with .subs type
- Prevents precondition failure when type doesn't match request kind

Author: hyochan

Sources/OpenIapModule+ObjC.swift

@@ -97,7 +97,7 @@ import StoreKit
     ) {
         Task {
             do {
-                let productType = type.flatMap { ProductQueryType(rawValue: $0) } ?? .inApp
+                // For purchase request, type must be .inApp
                 let iosProps = RequestPurchaseIosProps(
                     andDangerouslyFinishTransactionAutomatically: nil,
                     appAccountToken: nil,
@@ -109,7 +109,66 @@ import StoreKit
                     request: .purchase(
                         RequestPurchasePropsByPlatforms(android: nil, ios: iosProps)
                     ),
-                    type: productType
+                    type: .inApp
+                )
+
+                let result = try await requestPurchase(props)
+
+                switch result {
+                case .purchase(let purchase):
+                    if let purchase = purchase {
+                        let dictionary = OpenIapSerialization.purchase(purchase)
+                        completion(dictionary, nil)
+                    } else {
+                        completion(nil, nil)
+                    }
+                case .purchases(let purchases):
+                    if let firstPurchase = purchases?.first {
+                        let dictionary = OpenIapSerialization.purchase(firstPurchase)
+                        completion(dictionary, nil)
+                    } else {
+                        completion(nil, nil)
+                    }
+                case .none:
+                    completion(nil, nil)
+                }
+            } catch {
+                completion(nil, error)
+            }
+        }
+    }
+
+    @objc func requestSubscriptionWithSku(
+        _ sku: String,
+        offer: [String: Any]?,
+        completion: @escaping (Any?, Error?) -> Void
+    ) {
+        Task {
+            do {
+                // For subscription request, type must be .subs
+                let subscriptionOffer: SubscriptionOfferIOS? = if let offer = offer {
+                    SubscriptionOfferIOS(
+                        id: offer["id"] as? String,
+                        keyIdentifier: offer["keyIdentifier"] as? String,
+                        nonce: (offer["nonce"] as? String).flatMap { UUID(uuidString: $0) },
+                        signature: offer["signature"] as? String,
+                        timestamp: offer["timestamp"] as? Int64 ?? 0
+                    )
+                } else {
+                    nil
+                }
+
+                let iosProps = RequestSubscriptionIosProps(
+                    andDangerouslyFinishTransactionAutomatically: nil,
+                    appAccountToken: nil,
+                    sku: sku,
+                    withOffer: subscriptionOffer
+                )
+                let props = RequestPurchaseProps(
+                    request: .subscription(
+                        RequestPurchasePropsByPlatforms(android: nil, ios: iosProps)
+                    ),
+                    type: .subs
                 )
 
                 let result = try await requestPurchase(props)