feat(health): wire up NodeHostname, ConnectionEndpoint, TagQuality, ParkedMessageCount collectors

- AkkaHostedService: SetNodeHostname from NodeOptions
- DataConnectionActor: UpdateConnectionEndpoint on state transitions,
  track per-tag quality counts and UpdateTagQuality on value changes
- HealthReportSender: query StoreAndForwardStorage for parked message count
- StoreAndForwardStorage: add GetParkedMessageCountAsync()

src/ScadaLink.HealthMonitoring/HealthReportSender.cs

@@ -2,6 +2,7 @@ using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using ScadaLink.Commons.Messages.Health;
+using ScadaLink.StoreAndForward;
 
 namespace ScadaLink.HealthMonitoring;
 
@@ -16,6 +17,7 @@ public class HealthReportSender : BackgroundService
     private readonly HealthMonitoringOptions _options;
     private readonly ILogger<HealthReportSender> _logger;
     private readonly string _siteId;
+    private readonly StoreAndForwardStorage? _sfStorage;
     private long _sequenceNumber;
 
     public HealthReportSender(
@@ -23,13 +25,15 @@ public class HealthReportSender : BackgroundService
         IHealthReportTransport transport,
         IOptions<HealthMonitoringOptions> options,
         ILogger<HealthReportSender> logger,
-        ISiteIdentityProvider siteIdentityProvider)
+        ISiteIdentityProvider siteIdentityProvider,
+        StoreAndForwardStorage? sfStorage = null)
     {
         _collector = collector;
         _transport = transport;
         _options = options.Value;
         _logger = logger;
         _siteId = siteIdentityProvider.SiteId;
+        _sfStorage = sfStorage;
     }
 
     /// <summary>
@@ -54,6 +58,16 @@ public class HealthReportSender : BackgroundService
                 if (!_collector.IsActiveNode)
                     continue;
 
+                if (_sfStorage != null)
+                {
+                    try
+                    {
+                        var parkedCount = await _sfStorage.GetParkedMessageCountAsync();
+                        _collector.SetParkedMessageCount(parkedCount);
+                    }
+                    catch { /* Non-fatal — parked count will be 0 */ }
+                }
+
                 var seq = Interlocked.Increment(ref _sequenceNumber);
                 var report = _collector.CollectReport(_siteId);
 

src/ScadaLink.HealthMonitoring/ScadaLink.HealthMonitoring.csproj

@@ -16,6 +16,7 @@
 
   <ItemGroup>
     <ProjectReference Include="../ScadaLink.Commons/ScadaLink.Commons.csproj" />
+    <ProjectReference Include="../ScadaLink.StoreAndForward/ScadaLink.StoreAndForward.csproj" />
   </ItemGroup>
 
   <ItemGroup>