fix: improve maintenance and synchronize live conversations

backend/app/services/ticket.py

@@ -831,18 +831,19 @@ class TicketService:
             }, message_id=stored.id, source=MessageSource.SYSTEM)
             if not delivery.ok:
                 chat_repo.mark_delivery_failed(stored.id, delivery.reason)
-            if ticket.first_response_at is None:
-                ticket.first_response_at = datetime.now(timezone.utc)
-            if record_activity:
-                self._add_activity(
-                    ticket, TicketActivityType.CUSTOMER_NOTIFIED,
-                    actor_type=TicketActorType.SYSTEM,
-                    body=message,
-                    metadata={
-                        "session_id": str(session_record.session_id),
-                        "channel": channel,
-                    },
-                )
+            else:
+                if ticket.first_response_at is None:
+                    ticket.first_response_at = datetime.now(timezone.utc)
+                if record_activity:
+                    self._add_activity(
+                        ticket, TicketActivityType.CUSTOMER_NOTIFIED,
+                        actor_type=TicketActorType.SYSTEM,
+                        body=message,
+                        metadata={
+                            "session_id": str(session_record.session_id),
+                            "channel": channel,
+                        },
+                    )
         except Exception as e:
             logger.error(f"Customer notification failed for {ticket.display_number}: {e}")
             # Stored but the hand-over itself raised: don't let the thread