feat(client): 购买模型/仓库切 pay v2 契约（render_type 多态 + 分金额 + 订单列表）

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

client/lib/repositories/license_repository.dart

@@ -74,6 +74,46 @@ class LicenseRepository {
     }
   }
 
+  /// 取消一笔未支付订单（防 pending 单堆积）。仅管理员可用。
+  /// 返回 true=已取消；订单不存在（404）或不可取消（409，如已支付/已取消）
+  /// 视为业务性「取消不了」，返回 false 而非抛异常。
+  Future<bool> cancelPurchase(String outTradeNo) async {
+    try {
+      final resp = await _client.post('/license/purchase/$outTradeNo/cancel');
+      final data = resp.data['data'] as Map<String, dynamic>?;
+      return data?['canceled'] as bool? ?? false;
+    } on DioException catch (e) {
+      final status = e.response?.statusCode;
+      if (status == 404 || status == 409) return false;
+      throw AppException(
+        e.response?.data?['error'] as String? ?? '取消订单失败，请稍后重试',
+        statusCode: status,
+      );
+    }
+  }
+
+  /// 购买订单列表（订单管理 tab，分页 + 状态筛选）。仅管理员可用。
+  Future<PurchaseListResult> listPurchases({
+    int page = 1,
+    int pageSize = 20,
+    String? status,
+  }) async {
+    try {
+      final resp = await _client.get('/license/purchases', params: {
+        'page': page,
+        'page_size': pageSize,
+        if (status != null) 'status': status,
+      });
+      return PurchaseListResult.fromJson(
+          resp.data['data'] as Map<String, dynamic>);
+    } on DioException catch (e) {
+      throw AppException(
+        e.response?.data?['error'] as String? ?? '获取订单列表失败',
+        statusCode: e.response?.statusCode,
+      );
+    }
+  }
+
   /// 本店首月特惠是否已享用（购买弹窗据此置灰特惠档）。
   Future<bool> promoUsed() async {
     try {