feat(app): 接入金币充值与会员商品下单

lib/core/data/remote/commerce_api.dart

@@ -1,5 +1,7 @@
-// Author: fruit.com.cn
+// Author: fruit.com.cn
 
+import '../models/order.dart';
+import '../models/product.dart';
 import '../models/wallet.dart';
 import 'api_client.dart';
 
@@ -15,6 +17,31 @@ class CommerceApi {
     throw const ApiException(-1, '返回数据格式异常');
   }
 
+  /// 上架商品列表；`type` 传 `COIN_PACK` 或 `VIP`。
+  Future<List<AppProduct>> products({String? type}) async {
+    final data = await _client.get(
+      '/app/products',
+      query: type == null ? null : {'type': type},
+    );
+    if (data is List) {
+      return data
+          .whereType<Map<String, dynamic>>()
+          .map(AppProduct.fromJson)
+          .toList();
+    }
+    throw const ApiException(-1, '返回数据格式异常');
+  }
+
+  /// 创建充值订单，返回 `CREATED` 状态订单。
+  Future<AppOrder> createOrder(String productId) async {
+    final data = await _client.post(
+      '/app/orders',
+      body: {'productId': productId},
+    );
+    if (data is Map<String, dynamic>) return AppOrder.fromJson(data);
+    throw const ApiException(-1, '返回数据格式异常');
+  }
+
   Future<UnlockResult> unlock(String episodeId) async {
     final data = await _client.post('/app/episodes/$episodeId/unlock');
     if (data is Map<String, dynamic>) return UnlockResult.fromJson(data);