fix(force-recharge): 补充强充配置缺失的接口和数据库字段

- 订单管理：增加 payment_method 字段支持，合并代购订单逻辑
- 套餐系列分配：增加强充配置字段（enable_force_recharge、force_recharge_amount、force_recharge_trigger_type）
- 数据库迁移：添加 force_recharge_trigger_type 字段
- 测试：更新订单服务测试用例
- OpenSpec：归档 fix-force-recharge-missing-interfaces 变更

internal/service/shop_series_allocation/service.go

@@ -124,6 +124,18 @@ func (s *Service) Create(ctx context.Context, req *dto.CreateShopSeriesAllocatio
 			allocation.OneTimeCommissionValue = cfg.Value
 		}
 	}
+
+	// 处理强充配置
+	if req.EnableForceRecharge != nil {
+		allocation.EnableForceRecharge = *req.EnableForceRecharge
+	}
+	if req.ForceRechargeAmount != nil {
+		allocation.ForceRechargeAmount = *req.ForceRechargeAmount
+	}
+	if req.ForceRechargeTriggerType != nil {
+		allocation.ForceRechargeTriggerType = *req.ForceRechargeTriggerType
+	}
+
 	allocation.Creator = currentUserID
 
 	if err := s.allocationStore.Create(ctx, allocation); err != nil {
@@ -224,6 +236,17 @@ func (s *Service) Update(ctx context.Context, id uint, req *dto.UpdateShopSeries
 			allocation.OneTimeCommissionValue = 0
 		}
 	}
+
+	if req.EnableForceRecharge != nil {
+		allocation.EnableForceRecharge = *req.EnableForceRecharge
+	}
+	if req.ForceRechargeAmount != nil {
+		allocation.ForceRechargeAmount = *req.ForceRechargeAmount
+	}
+	if req.ForceRechargeTriggerType != nil {
+		allocation.ForceRechargeTriggerType = *req.ForceRechargeTriggerType
+	}
+
 	allocation.Updater = currentUserID
 
 	if configChanged {
@@ -399,10 +422,13 @@ func (s *Service) buildResponse(ctx context.Context, a *model.ShopSeriesAllocati
 			Mode:  a.BaseCommissionMode,
 			Value: a.BaseCommissionValue,
 		},
-		EnableOneTimeCommission: a.EnableOneTimeCommission,
-		Status:                  a.Status,
-		CreatedAt:               a.CreatedAt.Format(time.RFC3339),
-		UpdatedAt:               a.UpdatedAt.Format(time.RFC3339),
+		EnableOneTimeCommission:  a.EnableOneTimeCommission,
+		EnableForceRecharge:      a.EnableForceRecharge,
+		ForceRechargeAmount:      a.ForceRechargeAmount,
+		ForceRechargeTriggerType: a.ForceRechargeTriggerType,
+		Status:                   a.Status,
+		CreatedAt:                a.CreatedAt.Format(time.RFC3339),
+		UpdatedAt:                a.UpdatedAt.Format(time.RFC3339),
 	}
 
 	if a.EnableOneTimeCommission {