feat(admincli): add command for creating a user

src/FiscalOS.AdminCLI/Program.cs

@@ -1,11 +1,15 @@
-// TODO: We need a way to add
-// a user to the system with
-// a properly hashed password
-// so need something like this:
-//
-// 1. Ask for username
-// 2. Ask for user password
-// 3. Hash user password
-// 4. Save user to database
-
-Console.WriteLine("Hello, World!");
+await Host.CreateDefaultBuilder(args)
+  .ConfigureAppConfiguration(
+    static c => c.SetBasePath(AppContext.BaseDirectory)
+      .AddJsonFile("appsettings.json")
+      .AddEnvironmentVariables()
+  )
+  .ConfigureLogging(static c => c.ClearProviders())
+  .ConfigureServices(static (_, services) =>
+  {
+    services.AddSingleton(AnsiConsole.Console);
+    services.AddInfrastructure();
+    services.AddHostedService<App>();
+  })
+  .Build()
+  .StartAsync();