feat: add affiliate invite rebate flow and admin rebate-rate setting

backend/internal/service/payment_service.go

@@ -170,17 +170,18 @@ type TopUserStat struct {
 // --- Service ---
 
 type PaymentService struct {
-	providerMu      sync.Mutex
-	providersLoaded bool
-	entClient       *dbent.Client
-	registry        *payment.Registry
-	loadBalancer    payment.LoadBalancer
-	redeemService   *RedeemService
-	subscriptionSvc *SubscriptionService
-	configService   *PaymentConfigService
-	userRepo        UserRepository
-	groupRepo       GroupRepository
-	resumeService   *PaymentResumeService
+	providerMu       sync.Mutex
+	providersLoaded  bool
+	entClient        *dbent.Client
+	registry         *payment.Registry
+	loadBalancer     payment.LoadBalancer
+	redeemService    *RedeemService
+	subscriptionSvc  *SubscriptionService
+	configService    *PaymentConfigService
+	userRepo         UserRepository
+	groupRepo        GroupRepository
+	resumeService    *PaymentResumeService
+	affiliateService *AffiliateService
 }
 
 func NewPaymentService(entClient *dbent.Client, registry *payment.Registry, loadBalancer payment.LoadBalancer, redeemService *RedeemService, subscriptionSvc *SubscriptionService, configService *PaymentConfigService, userRepo UserRepository, groupRepo GroupRepository) *PaymentService {
@@ -189,6 +190,13 @@ func NewPaymentService(entClient *dbent.Client, registry *payment.Registry, load
 	return svc
 }
 
+func (s *PaymentService) SetAffiliateService(affiliateService *AffiliateService) {
+	if s == nil {
+		return
+	}
+	s.affiliateService = affiliateService
+}
+
 // --- Provider Registry ---
 
 // EnsureProviders lazily initializes the provider registry on first call.