fix: harden competitor create and batch kol stats

server/internal/tenant/app/brand_service.go

@@ -639,6 +639,20 @@ func (s *BrandService) ListCompetitors(ctx context.Context, brandID int64) ([]Co
 
 func (s *BrandService) CreateCompetitor(ctx context.Context, brandID int64, req CompetitorRequest) (*CompetitorResponse, error) {
 	actor := auth.MustActor(ctx)
+	req.Name = strings.TrimSpace(req.Name)
+	req.Website = normalizeOptionalString(req.Website)
+	req.Description = normalizeOptionalString(req.Description)
+	if req.Name == "" {
+		return nil, response.ErrBadRequest(40001, "invalid_params", "name is required")
+	}
+	exists, err := s.brandExists(ctx, actor.TenantID, brandID)
+	if err != nil {
+		return nil, err
+	}
+	if !exists {
+		return nil, response.ErrNotFound(40420, "brand_not_found", "brand not found")
+	}
+
 	var plJSON []byte
 	if req.ProductLinesJSON != nil {
 		plJSON = *req.ProductLinesJSON
@@ -646,11 +660,14 @@ func (s *BrandService) CreateCompetitor(ctx context.Context, brandID int64, req
 
 	var id int64
 	var ca interface{}
-	err := s.pool.QueryRow(ctx, `
+	err = s.pool.QueryRow(ctx, `
 		INSERT INTO competitors (tenant_id, brand_id, name, website, description, product_lines_json)
 		VALUES ($1, $2, $3, $4, $5, $6) RETURNING id, created_at
 	`, actor.TenantID, brandID, req.Name, req.Website, req.Description, plJSON).Scan(&id, &ca)
 	if err != nil {
+		if isForeignKeyConstraintError(err) {
+			return nil, response.ErrNotFound(40420, "brand_not_found", "brand not found")
+		}
 		return nil, response.ErrInternal(50010, "create_failed", "failed to create competitor")
 	}
 	invalidateBrandCaches(ctx, s.cache, actor.TenantID, brandID)

server/internal/tenant/app/kol_dashboard_service.go

@@ -111,19 +111,18 @@ func (s *KolDashboardService) PerPackage(ctx context.Context, actor auth.Actor)
 		usageByPackage[stat.PackageID] = stat
 	}
 
+	subscriberCounts, err := s.subRepo.CountActiveSubscriberTenantsByPackages(ctx, packageIDs)
+	if err != nil {
+		return nil, response.ErrInternal(50123, "kol_dashboard_subscriber_query_failed", err.Error())
+	}
+
 	result := make([]DashboardPackageStat, 0, len(packages))
 	for _, pkg := range packages {
-		subscribers, err := s.subRepo.ListActiveSubscribersForPackage(ctx, pkg.ID)
-		if err != nil {
-			return nil, response.ErrInternal(50123, "kol_dashboard_subscriber_query_failed", err.Error())
-		}
-
-		subscriberTenants := uniqueSubscriberTenants(subscribers)
 		usage := usageByPackage[pkg.ID]
 		result = append(result, DashboardPackageStat{
 			PackageID:         pkg.ID,
 			PackageName:       pkg.Name,
-			SubscriberTenants: subscriberTenants,
+			SubscriberTenants: subscriberCounts[pkg.ID],
 			UsageCount:        usage.Total,
 			FailureRate:       float64(usage.Failed) / float64(maxDashboardBase(usage.Total)),
 		})

server/internal/tenant/app/kol_package_service.go

@@ -80,9 +80,19 @@ func (s *KolPackageService) List(ctx context.Context, actor auth.Actor) ([]KolPa
 		return nil, response.ErrInternal(50062, "kol_package_query_failed", err.Error())
 	}
 
+	packageIDs := kolPackageIDs(packages)
+	promptCounts, err := s.packagePromptCounts(ctx, actor.TenantID, packageIDs)
+	if err != nil {
+		return nil, err
+	}
+	selfSubscriptions, err := s.packageSelfSubscriptions(ctx, actor.TenantID, packageIDs)
+	if err != nil {
+		return nil, err
+	}
+
 	result := make([]KolPackageResponse, 0, len(packages))
 	for _, pkg := range packages {
-		item, err := s.buildPackageResponse(ctx, profile, &pkg)
+		item, err := s.buildPackageResponseWithStats(profile, &pkg, promptCounts[pkg.ID], selfSubscriptions[pkg.ID])
 		if err != nil {
 			return nil, err
 		}
@@ -299,30 +309,31 @@ func (s *KolPackageService) buildPackageResponse(
 	ctx context.Context,
 	profile *repository.KolProfile,
 	pkg *repository.KolPackage,
+) (*KolPackageResponse, error) {
+	promptCounts, err := s.packagePromptCounts(ctx, pkg.TenantID, []int64{pkg.ID})
+	if err != nil {
+		return nil, err
+	}
+
+	selfSubscriptions, err := s.packageSelfSubscriptions(ctx, pkg.TenantID, []int64{pkg.ID})
+	if err != nil {
+		return nil, err
+	}
+
+	return s.buildPackageResponseWithStats(profile, pkg, promptCounts[pkg.ID], selfSubscriptions[pkg.ID])
+}
+
+func (s *KolPackageService) buildPackageResponseWithStats(
+	profile *repository.KolProfile,
+	pkg *repository.KolPackage,
+	promptCount int,
+	selfSubscription *repository.KolSubscription,
 ) (*KolPackageResponse, error) {
 	tags, err := decodeKolStringList(pkg.Tags)
 	if err != nil {
 		return nil, response.ErrInternal(50068, "kol_package_decode_failed", err.Error())
 	}
 
-	promptCount := 0
-	if s.promptRepo != nil {
-		prompts, err := s.promptRepo.ListByPackage(ctx, pkg.TenantID, pkg.ID)
-		if err != nil {
-			return nil, response.ErrInternal(50069, "kol_prompt_query_failed", err.Error())
-		}
-		promptCount = len(prompts)
-	}
-
-	var selfSubscription *KolSubscriptionResponse
-	if s.subRepo != nil {
-		sub, err := s.subRepo.GetActiveForTenant(ctx, pkg.TenantID, pkg.ID)
-		if err != nil {
-			return nil, response.ErrInternal(50093, "kol_subscription_query_failed", err.Error())
-		}
-		selfSubscription = newKolSubscriptionResponse(sub)
-	}
-
 	return &KolPackageResponse{
 		ID:               pkg.ID,
 		KolProfileID:     pkg.KolProfileID,
@@ -337,12 +348,48 @@ func (s *KolPackageService) buildPackageResponse(
 		Status:           pkg.Status,
 		PromptCount:      promptCount,
 		SubscriberCount:  0,
-		SelfSubscription: selfSubscription,
+		SelfSubscription: newKolSubscriptionResponse(selfSubscription),
 		CreatedAt:        pkg.CreatedAt,
 		UpdatedAt:        pkg.UpdatedAt,
 	}, nil
 }
 
+func (s *KolPackageService) packagePromptCounts(ctx context.Context, tenantID int64, packageIDs []int64) (map[int64]int, error) {
+	if s.promptRepo == nil {
+		return map[int64]int{}, nil
+	}
+	counts, err := s.promptRepo.CountByPackages(ctx, tenantID, packageIDs)
+	if err != nil {
+		return nil, response.ErrInternal(50069, "kol_prompt_query_failed", err.Error())
+	}
+	return counts, nil
+}
+
+func (s *KolPackageService) packageSelfSubscriptions(ctx context.Context, tenantID int64, packageIDs []int64) (map[int64]*repository.KolSubscription, error) {
+	result := make(map[int64]*repository.KolSubscription, len(packageIDs))
+	if s.subRepo == nil {
+		return result, nil
+	}
+
+	subscriptions, err := s.subRepo.ListActiveForTenantByPackages(ctx, tenantID, packageIDs)
+	if err != nil {
+		return nil, response.ErrInternal(50093, "kol_subscription_query_failed", err.Error())
+	}
+	for packageID, sub := range subscriptions {
+		subscription := sub
+		result[packageID] = &subscription
+	}
+	return result, nil
+}
+
+func kolPackageIDs(packages []repository.KolPackage) []int64 {
+	ids := make([]int64, 0, len(packages))
+	for _, pkg := range packages {
+		ids = append(ids, pkg.ID)
+	}
+	return ids
+}
+
 func normalizeKolOptionalString(value *string) *string {
 	if value == nil {
 		return nil