feat(scadabridge): add HTTP/1.1 metrics listener on site nodes (NodeOptions.MetricsPort=8082)

src/ZB.MOM.WW.ScadaBridge.Host/NodeOptions.cs

@@ -20,4 +20,6 @@ public class NodeOptions
     public int RemotingPort { get; set; } = 8081;
     /// <summary>Gets or sets the gRPC port for the site stream server.</summary>
     public int GrpcPort { get; set; } = 8083;
+    /// <summary>HTTP/1.1 port serving the Prometheus /metrics scrape endpoint on site nodes.</summary>
+    public int MetricsPort { get; set; } = 8082;
 }

src/ZB.MOM.WW.ScadaBridge.Host/Program.cs

@@ -293,6 +293,11 @@ try
         // Read GrpcPort from config (NodeOptions already has default 8083)
         var grpcPort = configuration.GetValue<int>("ScadaBridge:Node:GrpcPort", 8083);
 
+        // Read MetricsPort from config (NodeOptions already has default 8082).
+        // Separate HTTP/1.1 listener so a standard HTTP/1.1 Prometheus scraper can
+        // reach /metrics; the gRPC port stays HTTP/2-only below.
+        var metricsPort = configuration.GetValue<int>("ScadaBridge:Node:MetricsPort", 8082);
+
         // Configure Kestrel for HTTP/2 only on the gRPC port
         builder.WebHost.ConfigureKestrel(options =>
         {
@@ -300,6 +305,13 @@ try
             {
                 listenOptions.Protocols = Microsoft.AspNetCore.Server.Kestrel.Core.HttpProtocols.Http2;
             });
+
+            // Dedicated HTTP/1.1 (and HTTP/2) listener for the Prometheus /metrics
+            // scrape endpoint, reachable by an HTTP/1.1 scraper.
+            options.ListenAnyIP(metricsPort, listenOptions =>
+            {
+                listenOptions.Protocols = Microsoft.AspNetCore.Server.Kestrel.Core.HttpProtocols.Http1AndHttp2;
+            });
         });
 
         // gRPC server registration