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/ios/EryaoProducts.storekit

@@ -23,17 +23,17 @@
     {
       "displayPrice" : "6.00",
       "familyShareable" : false,
-      "internalID" : "basic_pack_001",
+      "internalID" : "starter_pack_001",
       "introductoryOffer" : null,
       "localizations" : [
         {
-          "description" : "基础信用点套餐",
-          "displayName" : "基础包",
+          "description" : "入门信用点套餐",
+          "displayName" : "入门包",
           "locale" : "zh_CN"
         }
       ],
-      "productID" : "com.meeyao.qianwen.basic_pack",
-      "referenceName" : "基础包",
+      "productID" : "com.meeyao.qianwen.starter_pack",
+      "referenceName" : "入门包",
       "type" : "Consumable"
     },
     {