fix: wire DCL connection state changes into ISiteHealthCollector

DataConnectionActor now calls UpdateConnectionHealth() on state
transitions (Connecting/Connected/Reconnecting) and UpdateTagResolution()
on connection establishment. DataConnectionManagerActor calls
RemoveConnection() on actor removal. Health reports now include
data connection statuses when instances are deployed with bindings.

src/ScadaLink.Host/Actors/AkkaHostedService.cs

@@ -219,9 +219,10 @@ akka {{
         IActorRef? dclManager = null;
         if (dclFactory != null)
         {
+            var healthCollector = _serviceProvider.GetRequiredService<ScadaLink.HealthMonitoring.ISiteHealthCollector>();
             dclManager = _actorSystem!.ActorOf(
                 Props.Create(() => new ScadaLink.DataConnectionLayer.Actors.DataConnectionManagerActor(
-                    dclFactory, dclOptions)),
+                    dclFactory, dclOptions, healthCollector)),
                 "dcl-manager");
             _logger.LogInformation("Data Connection Layer manager actor created");
         }