Add HttpClient registration to DI container

Added a call to `services.AddHttpClient();` in the `DependencyInjection` class within `DependencyInjection.cs`. This change registers the `HttpClient` service in the dependency injection container, allowing the application to use managed `HttpClient` instances.

src/ReC.Application/DependencyInjection.cs

@@ -22,6 +22,8 @@ public static class DependencyInjection
             cfg.LicenseKey = configOpt.LuckyPennySoftwareLicenseKey;
         });
 
+        services.AddHttpClient();
+
         return services;
     }