Add Dependency Injection for Future Updates

Program.cs

@@ -1,10 +1,22 @@
+using System.Net.Http.Headers;
 using System.Runtime.InteropServices;
 using FCPModUpdater;
 using FCPModUpdater.Commands;
+using FCPModUpdater.Infrastructure;
+using FCPModUpdater.Services;
+using Microsoft.Extensions.DependencyInjection;
 using Spectre.Console;
 using Spectre.Console.Cli;
 
-var app = new CommandApp();
+var services = new ServiceCollection();
+
+services.AddHttpClient<IGitHubApiService, GitHubApiService>(ConfigureGitHubClient);
+services.AddHttpClient<UpdateCheckService>(ConfigureGitHubClient);
+
+services.AddSingleton<IGitService, GitService>();
+services.AddSingleton<IModDiscoveryService, ModDiscoveryService>();
+
+var app = new CommandApp(new TypeRegistrar(services));
 
 app.Configure(config =>
 {
@@ -21,7 +33,6 @@ app.Configure(config =>
         .WithDescription("Update all FCP mods (non-interactive)")
         .WithExample("update")
         .WithExample("update", "--directory", "/path/to/RimWorld/Mods");
-    
 });
 
 app.SetDefaultCommand<ScanCommand>();
@@ -37,3 +48,14 @@ if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
 }
 
 return result;
+
+void ConfigureGitHubClient(HttpClient client)
+{
+    client.BaseAddress = new Uri("https://api.github.com");
+    client.DefaultRequestHeaders.UserAgent.ParseAdd($"FCPModUpdater/{AppVersion.SemanticVersion}");
+    client.DefaultRequestHeaders.Accept.ParseAdd("application/vnd.github+json");
+
+    var token = Environment.GetEnvironmentVariable("GITHUB_TOKEN");
+    if (!string.IsNullOrEmpty(token))
+        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
+}