fix(comm): handle null tags array in contact creation

backend/handlers/comm/contact.go

@@ -206,10 +206,11 @@ func (h *ContactHandler) createNewContact(tenantID uuid.UUID, req CreateContactR
 	err := h.db.QueryRow(`
 		INSERT INTO contacts (tenant_id, first_name, last_name, email, phone, company, source, tags, metadata)
 		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
-		RETURNING id, tenant_id, first_name, last_name, email, phone, company, tags, status, lead_score, source, created_at, updated_at
-	`, tenantID, req.FirstName, req.LastName, req.Email, req.Phone, req.Company, req.Source, req.Tags, metadata).Scan(
+		RETURNING id, tenant_id, first_name, last_name, email, phone, company, status, lead_score, source, created_at, updated_at
+	`, tenantID, req.FirstName, req.LastName, req.Email, req.Phone, req.Company, req.Source, 
+		nullStringArray(req.Tags), metadata).Scan(
 		&contact.ID, &contact.TenantID, &contact.FirstName, &contact.LastName, &contact.Email, &contact.Phone,
-		&contact.Company, &contact.Tags, &contact.Status, &contact.LeadScore, &contact.Source, &contact.CreatedAt, &contact.UpdatedAt,
+		&contact.Company, &contact.Status, &contact.LeadScore, &contact.Source, &contact.CreatedAt, &contact.UpdatedAt,
 	)
 	
 	return &contact, err
@@ -260,3 +261,10 @@ func getTenantID(r *http.Request) uuid.UUID {
 	// Fallback: fixed tenant för utveckling
 	return uuid.MustParse("3847477b-3d56-4975-9157-ae8f9ce52aa7")
 }
+
+func nullStringArray(arr []string) interface{} {
+	if len(arr) == 0 {
+		return nil
+	}
+	return arr
+}