op14: add todo to reduce data sent

extra/admin-api/Spacebar.Offload/Controllers/Op14Controller.cs

@@ -73,6 +73,7 @@ public class Op14Controller(ILogger<Op12Controller> logger, SpacebarAspNetAuthen
                 // TODO: handle subscriptions
                 // TODO: handle channel permissions
                 // TODO: handle channels at all
+                // TODO: reduce the amount of duplicate User objects sent?
             };
     }