fix(invitation): 邀请返利改用实际结算利润并修正提号基准

backend/internal/modules/invitation/repository.go

@@ -369,6 +369,14 @@ func (r *Repository) processOrderInvitationRebate(ctx context.Context, tx *gorm.
 	orderGrossProfitCent := order.RentAmountCent - order.OwnerRentAmountCent
 	if opts.GrossProfitCent != nil {
 		orderGrossProfitCent = *opts.GrossProfitCent
+	} else {
+		// 正常结账、仲裁等终态都已落定实际结账单；未显式传基数时优先按实际平台利润，
+		// 避免再次用订单创建时的预收毛利快照给零消耗结账发返利。
+		var committedCheckout model.OrderCheckout
+		if err := tx.Where("order_id = ? AND status IN ?", order.ID, []string{"accepted", "settled"}).
+			Order("id DESC").First(&committedCheckout).Error; err == nil {
+			orderGrossProfitCent = committedCheckout.PlatformFeeCent
+		}
 	}
 	if orderGrossProfitCent <= 0 {
 		return nil

backend/internal/modules/invitation/repository_test.go

@@ -20,6 +20,7 @@ func setupTestDB(t *testing.T) *gorm.DB {
 		&model.InvitationRebateConfig{},
 		&model.InvitationRebateLedger{},
 		&model.RentalOrder{},
+		&model.OrderCheckout{},
 		&model.DistributionSite{},
 		&model.DistributionOrderParty{},
 		&model.WalletAccount{},
@@ -262,6 +263,57 @@ func TestProcessOrderInvitationRebateUsesActualProfitBasis(t *testing.T) {
 	}
 }
 
+func TestProcessOrderInvitationRebateFallsBackToCommittedCheckoutProfit(t *testing.T) {
+	db := setupTestDB(t)
+	inviter := model.User{Phone: "13800000021", RealnameStatus: "verified", Status: "active"}
+	if err := db.Create(&inviter).Error; err != nil {
+		t.Fatalf("创建邀请人失败: %v", err)
+	}
+	seller := model.User{Phone: "13800000022", RealnameStatus: "verified", Status: "active"}
+	if err := db.Create(&seller).Error; err != nil {
+		t.Fatalf("创建卖家失败: %v", err)
+	}
+	verifiedAt := time.Now().AddDate(0, 0, -2).Truncate(time.Second)
+	if err := db.Create(&model.UserInvitation{
+		InviterID: inviter.ID, InviteeID: seller.ID, Status: StatusActive, VerifiedAt: &verifiedAt,
+	}).Error; err != nil {
+		t.Fatalf("创建邀请关系失败: %v", err)
+	}
+	order := model.RentalOrder{
+		OrderNo:             fmt.Sprintf("ORD-COMMITTED-%d", time.Now().UnixNano()),
+		OwnerID:             seller.ID,
+		RenterID:            99999,
+		Status:              "completed",
+		SettlementStatus:    "settled",
+		RentAmountCent:      10000,
+		OwnerRentAmountCent: 8000,
+	}
+	if err := db.Create(&order).Error; err != nil {
+		t.Fatalf("创建订单失败: %v", err)
+	}
+	if err := db.Create(&model.OrderCheckout{
+		OrderID:             order.ID,
+		Status:              "accepted",
+		RentAmountCent:      2000,
+		OwnerRentAmountCent: 1700,
+		PlatformFeeCent:     300,
+	}).Error; err != nil {
+		t.Fatalf("创建已确认结账单失败: %v", err)
+	}
+
+	if err := NewRepository(db).ProcessOrderInvitationRebate(t.Context(), db, order.ID); err != nil {
+		t.Fatalf("返利处理失败: %v", err)
+	}
+	var ledger model.InvitationRebateLedger
+	if err := db.Where("order_id = ? AND trade_role = 'seller'", order.ID).First(&ledger).Error; err != nil {
+		t.Fatalf("查询返利流水失败: %v", err)
+	}
+	if ledger.OrderProfitBasisCent != 300 || ledger.SingleSideBasisCent != 150 || ledger.RebateAmountCent != 90 {
+		t.Fatalf("返利基数/单边/金额 = %d/%d/%d, want 300/150/90",
+			ledger.OrderProfitBasisCent, ledger.SingleSideBasisCent, ledger.RebateAmountCent)
+	}
+}
+
 func TestCrossSiteDistributionRebate(t *testing.T) {
 	db := setupTestDB(t)
 	repo := NewRepository(db)