fix(comm): handle null next_action fields in lead creation

backend/handlers/comm/lead.go

@@ -90,6 +90,8 @@ func (h *LeadHandler) CreateLead(w http.ResponseWriter, r *http.Request) {
 	sourceMetadata, _ := json.Marshal(req.SourceMetadata)
 
 	var lead Lead
+	var nextActionAt *time.Time
+	var nextActionType sql.NullString
 	err := h.db.QueryRow(`
 		INSERT INTO leads (tenant_id, contact_id, conversation_id, source, source_metadata, 
 		                   interest, product, urgency, customer_type, tags, status)
@@ -101,9 +103,15 @@ func (h *LeadHandler) CreateLead(w http.ResponseWriter, r *http.Request) {
 		req.Interest, req.Product, req.Urgency, req.CustomerType, nullStringArray(req.Tags)).Scan(
 		&lead.ID, &lead.TenantID, &lead.ContactID, &lead.ConversationID, &lead.Source, &lead.Status,
 		&lead.Interest, &lead.Product, &lead.Urgency, &lead.CustomerType, &lead.Owner,
-		&lead.LeadScore, &lead.QualificationComplete, &lead.LastInteractionAt, &lead.NextActionAt,
-		&lead.NextActionType, &lead.Tags, &lead.CreatedAt, &lead.UpdatedAt,
+		&lead.LeadScore, &lead.QualificationComplete, &lead.LastInteractionAt, &nextActionAt,
+		&nextActionType, &lead.Tags, &lead.CreatedAt, &lead.UpdatedAt,
 	)
+	if nextActionAt != nil {
+		lead.NextActionAt = nextActionAt
+	}
+	if nextActionType.Valid {
+		lead.NextActionType = nextActionType.String
+	}
 	if err != nil {
 		log.Error().Err(err).Msg("Failed to create lead")
 		writeError(w, http.StatusInternalServerError, "failed to create lead")