feat: wire all health metrics and add instance counts to dashboard

Wired ISiteHealthCollector calls for script errors (ScriptExecutionActor),
alarm eval errors (AlarmActor), dead letters (DeadLetterMonitorActor), and
S&F buffer depth placeholder. Added instance count tracking (deployed/
enabled/disabled) to SiteHealthReport via DeploymentManagerActor. Updated
Health Dashboard UI to show instance counts per site. All metrics flow
through the existing health report pipeline via ClusterClient.

tests/ScadaLink.Commons.Tests/Messages/MessageConventionTests.cs

@@ -98,7 +98,7 @@ public class MessageConventionTests
             },
             0, 0,
             new Dictionary<string, int> { ["queue1"] = 5 },
-            0);
+            0, 0, 0, 0);
 
         var json = JsonSerializer.Serialize(msg);
         var deserialized = JsonSerializer.Deserialize<ScadaLink.Commons.Messages.Health.SiteHealthReport>(json);

tests/ScadaLink.HealthMonitoring.Tests/CentralHealthAggregatorTests.cs

@@ -50,7 +50,10 @@ public class CentralHealthAggregatorTests
             ScriptErrorCount: 0,
             AlarmEvaluationErrorCount: 0,
             StoreAndForwardBufferDepths: new Dictionary<string, int>(),
-            DeadLetterCount: 0);
+            DeadLetterCount: 0,
+            DeployedInstanceCount: 0,
+            EnabledInstanceCount: 0,
+            DisabledInstanceCount: 0);
 
     [Fact]
     public void ProcessReport_StoresState_ForNewSite()

tests/ScadaLink.IntegrationTests/ObservabilityTests.cs

@@ -100,7 +100,10 @@ public class ObservabilityTests : IClassFixture<ScadaLinkWebApplicationFactory>
                 ["ext-system"] = 15,
                 ["notification"] = 2
             },
-            DeadLetterCount: 5);
+            DeadLetterCount: 5,
+            DeployedInstanceCount: 0,
+            EnabledInstanceCount: 0,
+            DisabledInstanceCount: 0);
 
         // Metric type 1: Data connection health
         Assert.Equal(2, report.DataConnectionStatuses.Count);
@@ -141,7 +144,7 @@ public class ObservabilityTests : IClassFixture<ScadaLinkWebApplicationFactory>
             "site-01", 1, DateTimeOffset.UtcNow,
             new Dictionary<string, ConnectionHealth>(),
             new Dictionary<string, TagResolutionStatus>(),
-            0, 0, new Dictionary<string, int>(), 0));
+            0, 0, new Dictionary<string, int>(), 0, 0, 0, 0));
 
         var state = aggregator.GetSiteState("site-01");
         Assert.NotNull(state);
@@ -152,7 +155,7 @@ public class ObservabilityTests : IClassFixture<ScadaLinkWebApplicationFactory>
             "site-01", 2, DateTimeOffset.UtcNow,
             new Dictionary<string, ConnectionHealth>(),
             new Dictionary<string, TagResolutionStatus>(),
-            3, 0, new Dictionary<string, int>(), 0));
+            3, 0, new Dictionary<string, int>(), 0, 0, 0, 0));
 
         state = aggregator.GetSiteState("site-01");
         Assert.Equal(2, state!.LastSequenceNumber);
@@ -174,7 +177,7 @@ public class ObservabilityTests : IClassFixture<ScadaLinkWebApplicationFactory>
                 "site-01", seq, DateTimeOffset.UtcNow,
                 new Dictionary<string, ConnectionHealth>(),
                 new Dictionary<string, TagResolutionStatus>(),
-                seq, 0, new Dictionary<string, int>(), 0));
+                seq, 0, new Dictionary<string, int>(), 0, 0, 0, 0));
         }
 
         var state = aggregator.GetSiteState("site-01");

tests/ScadaLink.PerformanceTests/HealthAggregationTests.cs

@@ -53,7 +53,10 @@ public class HealthAggregationTests
                 {
                     ["ext-system"] = i * 2
                 },
-                DeadLetterCount: 0);
+                DeadLetterCount: 0,
+                DeployedInstanceCount: 0,
+                EnabledInstanceCount: 0,
+                DisabledInstanceCount: 0);
 
             _aggregator.ProcessReport(report);
         }
@@ -83,7 +86,10 @@ public class HealthAggregationTests
                     ScriptErrorCount: seq % 5 == 0 ? 1 : 0,
                     AlarmEvaluationErrorCount: 0,
                     StoreAndForwardBufferDepths: new Dictionary<string, int>(),
-                    DeadLetterCount: 0);
+                    DeadLetterCount: 0,
+                DeployedInstanceCount: 0,
+                EnabledInstanceCount: 0,
+                DisabledInstanceCount: 0);
 
                 _aggregator.ProcessReport(report);
             }
@@ -111,14 +117,14 @@ public class HealthAggregationTests
             siteId, 10, DateTimeOffset.UtcNow,
             new Dictionary<string, ConnectionHealth>(),
             new Dictionary<string, TagResolutionStatus>(),
-            5, 0, new Dictionary<string, int>(), 0));
+            5, 0, new Dictionary<string, int>(), 0, 0, 0, 0));
 
         // Send stale report with seq 5 — should be rejected
         _aggregator.ProcessReport(new SiteHealthReport(
             siteId, 5, DateTimeOffset.UtcNow,
             new Dictionary<string, ConnectionHealth>(),
             new Dictionary<string, TagResolutionStatus>(),
-            99, 0, new Dictionary<string, int>(), 0));
+            99, 0, new Dictionary<string, int>(), 0, 0, 0, 0));
 
         var state = _aggregator.GetSiteState(siteId);
         Assert.NotNull(state);

tests/ScadaLink.SiteRuntime.Tests/ScadaLink.SiteRuntime.Tests.csproj

@@ -26,6 +26,7 @@
   <ItemGroup>
     <ProjectReference Include="../../src/ScadaLink.SiteRuntime/ScadaLink.SiteRuntime.csproj" />
     <ProjectReference Include="../../src/ScadaLink.Commons/ScadaLink.Commons.csproj" />
+    <ProjectReference Include="../../src/ScadaLink.HealthMonitoring/ScadaLink.HealthMonitoring.csproj" />
   </ItemGroup>
 
 </Project>