Add Windows Service support to the MassTransit Connector host (#343)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: danielmarbach <174258+danielmarbach@users.noreply.github.com>

Author: Copilot

src/ServiceControl.Connector.MassTransit.Host/Commands/StartupCommand.cs

@@ -3,6 +3,7 @@ namespace ServiceControl.Connector.MassTransit.Host.Commands;
 using System.CommandLine;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Hosting.WindowsServices;
 using Microsoft.Extensions.Logging;
 using NServiceBus.Extensions.Logging;
 using ServiceControl.Connector.MassTransit;
@@ -43,6 +44,9 @@ async Task<int> InternalHandler(RunMode runMode, bool isConsole, string[] connec
         var builder = Host.CreateApplicationBuilder(connectorArgs);
         builder.UseMassTransitConnector(runMode == RunMode.Setup);
 
+        // Registers WindowsServiceLifetime and EventLog logging when running as a Windows Service; no-op otherwise.
+        builder.Services.AddWindowsService();
+
         if (isConsole)
         {
             builder.Logging.AddSimpleConsole(o =>
@@ -51,7 +55,7 @@ async Task<int> InternalHandler(RunMode runMode, bool isConsole, string[] connec
                 o.IncludeScopes = true;
             });
         }
-        else
+        else if (!WindowsServiceHelpers.IsWindowsService())
         {
             builder.Logging.AddSystemdConsole();
         }

src/ServiceControl.Connector.MassTransit.Host/ServiceControl.Connector.MassTransit.Host.csproj

@@ -15,6 +15,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="9.0.14" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.WindowsServices" Version="9.0.14" />
     <PackageReference Include="Microsoft.Extensions.Options.DataAnnotations" Version="9.0.14" />
     <PackageReference Include="NServiceBus.Extensions.Logging" Version="3.0.1" />
     <PackageReference Include="System.CommandLine" Version="2.0.4" />