feat(scripts): realign Test Run with runtime API, add anonymous-object calls and instance binding

The Test Run sandbox and Monaco analysis modelled a script API that had
drifted from the site runtime's ScriptGlobals, so real scripts failed to
compile in Test Run. Realign both to the runtime surface
(Instance/Scripts/ExternalSystem/Attributes/Children/Parent) and drop the
duplicate ScriptHost stub so the two cannot diverge again.

- Script calls (Scripts.CallShared, Instance.CallScript, Route.To().Call)
  accept an anonymous object instead of a hand-built dictionary, via a
  shared ScriptArgs normalizer; existing dictionary calls still compile.
- Test Run can optionally bind to a deployed instance, so Instance/
  Attributes/CallScript route to it cross-site; adds site-side
  RouteToGetAttributes/RouteToSetAttributes handlers.
- Adds Test Run panels to the API method and template script editors.
- Fixes the TestDatabaseQuery seed script, which queried a table that
  never existed.

Also commits unrelated in-progress work already in the tree: the health
monitoring report loop, site streaming changes, and the Admin/Design
data-connection and SMTP page reorganization.

src/ScadaLink.Host/Actors/AkkaHostedService.cs

@@ -175,6 +175,11 @@ akka {{
     /// </summary>
     private void RegisterCentralActors()
     {
+        // Feed this central node's hostname into the local health collector so
+        // the CentralHealthReportLoop's report identifies the active node.
+        var centralHealthCollector = _serviceProvider.GetService<ScadaLink.HealthMonitoring.ISiteHealthCollector>();
+        centralHealthCollector?.SetNodeHostname(_nodeOptions.NodeHostname);
+
         var siteClientFactory = new DefaultSiteClientFactory();
         var centralCommActor = _actorSystem!.ActorOf(
             Props.Create(() => new CentralCommunicationActor(_serviceProvider, siteClientFactory)),

src/ScadaLink.Host/Health/AkkaClusterNodeProvider.cs

@@ -20,6 +20,19 @@ public class AkkaClusterNodeProvider : IClusterNodeProvider
         _siteRole = siteRole;
     }
 
+    public bool SelfIsPrimary
+    {
+        get
+        {
+            var system = _akkaService.ActorSystem;
+            if (system == null) return false;
+            var cluster = Cluster.Get(system);
+            if (cluster.SelfMember.Status != MemberStatus.Up) return false;
+            var leader = cluster.State.Leader;
+            return leader != null && leader.Equals(cluster.SelfAddress);
+        }
+    }
+
     public IReadOnlyList<NodeStatus> GetClusterNodes()
     {
         var system = _akkaService.ActorSystem;

src/ScadaLink.Host/Program.cs

@@ -94,6 +94,14 @@ try
         builder.Services.AddSingleton<AkkaHostedService>();
         builder.Services.AddHostedService(sp => sp.GetRequiredService<AkkaHostedService>());
 
+        // Cluster node status provider scoped to the Central role — feeds the
+        // CentralHealthReportLoop so the central cluster appears on /monitoring/health.
+        builder.Services.AddSingleton<IClusterNodeProvider>(sp =>
+        {
+            var akkaService = sp.GetRequiredService<AkkaHostedService>();
+            return new AkkaClusterNodeProvider(akkaService, "Central");
+        });
+
         // Options binding
         SiteServiceRegistration.BindSharedOptions(builder.Services, builder.Configuration);
         builder.Services.Configure<SecurityOptions>(builder.Configuration.GetSection("ScadaLink:Security"));