feat(payment): 优化套餐配置和支付服务

- 简化套餐配置结构，删除冗余的 default.yaml 和 us.yaml
- 优化 Apple IAP 服务和验证逻辑
- 更新套餐数据模型和协议文档
- 添加支付相关测试用例

apps/lib/features/payments/data/services/apple_iap_service.dart

@@ -14,25 +14,11 @@ import '../models/apple_purchase_models.dart';
 
 enum PurchaseFlowState { idle, purchasing, verifying, success, failed }
 
-class PurchaseResult {
-  const PurchaseResult({
-    required this.state,
-    this.creditsAdded,
-    this.errorMessage,
-  });
-
-  final PurchaseFlowState state;
-  final int? creditsAdded;
-  final String? errorMessage;
-}
-
 class AppleIapService with ChangeNotifier {
-  AppleIapService({
-    required ApiClient apiClient,
-    required String userId,
-  })  : _paymentApi = ApplePaymentApi(apiClient: apiClient),
-        _inAppPurchase = InAppPurchase.instance,
-        _appAccountToken = _hashUserId(userId);
+  AppleIapService({required ApiClient apiClient, required String userId})
+    : _paymentApi = ApplePaymentApi(apiClient: apiClient),
+      _inAppPurchase = InAppPurchase.instance,
+      _appAccountToken = _hashUserId(userId);
 
   final ApplePaymentApi _paymentApi;
   final InAppPurchase _inAppPurchase;
@@ -116,7 +102,7 @@ class AppleIapService with ChangeNotifier {
     );
 
     if (!bought) {
-      _setError('Failed to initiate purchase');
+      _setState(PurchaseFlowState.idle);
       return false;
     }
 
@@ -130,19 +116,62 @@ class AppleIapService with ChangeNotifier {
   }
 
   Future<void> _handlePurchase(PurchaseDetails purchase) async {
-    switch (purchase.status) {
-      case PurchaseStatus.purchased:
-        await _verifyAndComplete(purchase);
-      case PurchaseStatus.canceled:
-        await _inAppPurchase.completePurchase(purchase);
-        _setState(PurchaseFlowState.idle);
-      case PurchaseStatus.error:
-        await _inAppPurchase.completePurchase(purchase);
-        _setError(purchase.error?.message ?? 'Purchase failed');
-      case PurchaseStatus.pending:
-        _setState(PurchaseFlowState.purchasing);
-      case PurchaseStatus.restored:
-        await _inAppPurchase.completePurchase(purchase);
+    try {
+      switch (purchase.status) {
+        case PurchaseStatus.purchased:
+          await _verifyAndComplete(purchase);
+        case PurchaseStatus.canceled:
+          await _completePurchaseSafely(purchase);
+          _setState(PurchaseFlowState.idle);
+        case PurchaseStatus.error:
+          final errorCode = purchase.error?.code;
+          final isUserCancel = errorCode == '2';
+          if (isUserCancel) {
+            await _completePurchaseSafely(purchase);
+            _setState(PurchaseFlowState.idle);
+          } else {
+            _logger.warning(
+              message: 'Purchase error',
+              extra: {
+                'errorCode': errorCode,
+                'errorMessage': purchase.error?.message,
+              },
+            );
+            await _completePurchaseSafely(purchase);
+            _setError(purchase.error?.message ?? 'Purchase failed');
+          }
+        case PurchaseStatus.pending:
+          _setState(PurchaseFlowState.purchasing);
+        case PurchaseStatus.restored:
+          await _completePurchaseSafely(purchase);
+      }
+    } catch (e, stackTrace) {
+      _logger.error(
+        message: 'Failed to handle purchase',
+        error: e,
+        stackTrace: stackTrace,
+        extra: {
+          'productID': purchase.productID,
+          'purchaseID': purchase.purchaseID,
+          'status': purchase.status.name,
+        },
+      );
+      _setState(PurchaseFlowState.idle);
+    }
+  }
+
+  Future<void> _completePurchaseSafely(PurchaseDetails purchase) async {
+    try {
+      await _inAppPurchase.completePurchase(purchase);
+    } catch (e, stackTrace) {
+      _logger.warning(
+        message: 'completePurchase failed (likely null purchaseID): $e',
+        stackTrace: stackTrace,
+        extra: {
+          'productID': purchase.productID,
+          'purchaseID': purchase.purchaseID,
+        },
+      );
     }
   }
 
@@ -178,7 +207,12 @@ class AppleIapService with ChangeNotifier {
         message: 'Purchase verification failed',
         error: e,
         stackTrace: stackTrace,
-        extra: {'transactionId': purchase.purchaseID},
+        extra: {
+          'transactionId': purchase.purchaseID,
+          'productID': purchase.productID,
+          'errorType': e.runtimeType.toString(),
+          'errorMessage': e.toString(),
+        },
       );
 
       if (_isRetryableError(e)) {
@@ -216,7 +250,7 @@ class AppleIapService with ChangeNotifier {
   String _productCodeFromStoreKitId(String storeKitId) {
     return switch (storeKitId) {
       'com.meeyao.qianwen.new_user_pack' => 'new_user_pack',
-      'com.meeyao.qianwen.basic_pack' => 'basic_pack',
+      'com.meeyao.qianwen.starter_pack' => 'starter_pack',
       'com.meeyao.qianwen.popular_pack' => 'popular_pack',
       'com.meeyao.qianwen.premium_pack' => 'premium_pack',
       _ => storeKitId,