feat: Initialize Zastava Webhook service with TLS and Authority authentication

- Added Program.cs to set up the web application with Serilog for logging, health check endpoints, and a placeholder admission endpoint.
- Configured Kestrel server to use TLS 1.3 and handle client certificates appropriately.
- Created StellaOps.Zastava.Webhook.csproj with necessary dependencies including Serilog and Polly.
- Documented tasks in TASKS.md for the Zastava Webhook project, outlining current work and exit criteria for each task.

src/StellaOps.Excititor.Connectors.MSRC.CSAF/DependencyInjection/MsrcConnectorServiceCollectionExtensions.cs

@@ -4,9 +4,12 @@ using System.Net.Http;
 using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Options;
+using StellaOps.Excititor.Connectors.Abstractions;
 using StellaOps.Excititor.Connectors.MSRC.CSAF.Authentication;
 using StellaOps.Excititor.Connectors.MSRC.CSAF.Configuration;
 using System.IO.Abstractions;
+using StellaOps.Excititor.Core;
 
 namespace StellaOps.Excititor.Connectors.MSRC.CSAF.DependencyInjection;
 
@@ -33,7 +36,22 @@ public static class MsrcConnectorServiceCollectionExtensions
                 AutomaticDecompression = DecompressionMethods.All,
             });
 
+        services.AddHttpClient(MsrcConnectorOptions.ApiClientName)
+            .ConfigureHttpClient((provider, client) =>
+            {
+                var options = provider.GetRequiredService<IOptions<MsrcConnectorOptions>>().Value;
+                client.BaseAddress = options.BaseUri;
+                client.Timeout = TimeSpan.FromSeconds(60);
+                client.DefaultRequestHeaders.UserAgent.ParseAdd("StellaOps.Excititor.Connectors.MSRC.CSAF/1.0");
+                client.DefaultRequestHeaders.Accept.ParseAdd("application/json");
+            })
+            .ConfigurePrimaryHttpMessageHandler(static () => new HttpClientHandler
+            {
+                AutomaticDecompression = DecompressionMethods.All,
+            });
+
         services.AddSingleton<IMsrcTokenProvider, MsrcTokenProvider>();
+        services.AddSingleton<IVexConnector, MsrcCsafConnector>();
 
         return services;
     }