docs: changelog

Author: hyochan

CHANGELOG.md

@@ -5,29 +5,46 @@
 ### Features
 
 - **OpenIAP Compliance**: Implemented changes from [expo-iap PR #158](https://github.com/hyochan/expo-iap/pull/158) for standardized transaction identification
+
   - Added `id` field to `Purchase` class that maps to `transactionId` for OpenIAP compliance
   - Updated native implementations to include `id` field in purchase responses
   - Enhanced `finishTransaction` to accept `Purchase` objects directly
 
+- **Unified Purchase Token**: Cross-platform server validation support
+  - Added unified `purchaseToken` field for both iOS (JWS) and Android (purchase token)
+  - iOS now includes JWS representation for server-side validation
+  - Deprecated `jwsRepresentationIOS` and `purchaseTokenAndroid` in favor of `purchaseToken`
+  - Simplified cross-platform server validation workflow
+
 ### Improvements
 
 - **Transaction Management**: Simplified transaction finishing flow
+
   - `finishTransaction` now accepts `Purchase` objects directly, preserving all purchase data
   - Removed unnecessary `PurchasedItem` to `Purchase` conversions
   - Improved transaction ID handling with proper fallback logic
+  - Fixed duplicate transaction events with processed transaction tracking
 
 - **iOS StoreKit 2**: Complete StoreKit 2 implementation
+
   - Removed transaction caching in favor of direct StoreKit 2 API usage
   - Improved transaction search using `Transaction.all`
   - Added comprehensive debug logging for troubleshooting
   - Enhanced date handling for purchase timestamps
+  - Fixed transaction ID issues by removing StoreKit Configuration dependency
 
 - **Date Handling**: Fixed date display issues
+
   - Fixed "1970-01-01" date issue in Available Purchases
-  - Fixed "Unknown" date issue in Purchase History  
+  - Fixed "Unknown" date issue in Purchase History
   - Improved date parsing to handle multiple formats (ISO 8601, milliseconds, DateTime objects)
   - Consistent date handling across Android and iOS platforms
 
+- **Error Handling**: Enhanced error reporting
+  - Added comprehensive purchase-error events following expo-iap patterns
+  - Better error handling for both iOS and Android platforms
+  - Improved duplicate event prevention
+
 ### Bug Fixes
 
 - **Android**: Added missing `transactionId` field in `getPurchaseHistoryByType` response
@@ -52,19 +69,21 @@ None - This version maintains backward compatibility while adding new features.
 If you're upgrading from 6.1.x:
 
 1. **Transaction Finishing**: You can now pass `Purchase` objects directly to `finishTransaction()`:
+
    ```dart
    // Old way (still works)
    await _iap.finishTransaction(purchasedItem, isConsumable: true);
-   
+
    // New way (recommended)
    await _iap.finishTransaction(purchase, isConsumable: true);
    ```
 
 2. **Transaction ID**: Use the `id` field for OpenIAP compliance:
+
    ```dart
    // OpenIAP compliant way
    final transactionId = purchase.id;
-   
+
    // Legacy way (still works)
    final transactionId = purchase.transactionId;
    ```