Refactor backdoor configuration handling

Removed the `AddBackdoors` method from `DependencyInjection.cs` and replaced its usage in `Program.cs` with `Configure<Backdoor>`. Updated `using` directives to include `Microsoft.Extensions.DependencyInjection`. Added a new `BackdoorParams` class to encapsulate backdoor configuration settings.

src/DigitalData.Auth.API/Config/BackdoorParams.cs

@@ -0,0 +1,8 @@
+using DigitalData.Auth.API.Models;
+
+namespace DigitalData.Auth.API.Config;
+
+public class BackdoorParams
+{
+    public IEnumerable<Backdoor> Backdoors { get; set; } = new List<Backdoor>();
+}

src/DigitalData.Auth.API/Models/DependencyInjection.cs

@@ -1,12 +0,0 @@
-using Microsoft.Extensions.Options;
-
-namespace DigitalData.Auth.API.Models;
-
-public static class DependencyInjection
-{
-    public static IServiceCollection AddBackdoors(this IServiceCollection services, IConfiguration configuration)
-    {
-        var backdoors = configuration.GetSection("backdoors").Get<IEnumerable<Backdoor>>() ?? Enumerable.Empty<Backdoor>();
-        return services.AddSingleton(Options.Create(backdoors));
-    }
-}

src/DigitalData.Auth.API/Program.cs

@@ -10,6 +10,7 @@ using DigitalData.Core.Security.Extensions;
 using DigitalData.UserManager.Application;
 using DigitalData.UserManager.Application.DTOs.User;
 using Microsoft.AspNetCore.Authentication.JwtBearer;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.IdentityModel.JsonWebTokens;
 using Microsoft.IdentityModel.Tokens;
 using Microsoft.OpenApi.Models;
@@ -34,7 +35,7 @@ try
     var apiParams = config.Get<AuthApiParams>() ?? throw new InvalidOperationException("AuthApiOptions is missing or invalid in appsettings.");
 
     // Add services to the container.
-    builder.Services.AddBackdoors(config);
+    builder.Services.Configure<Backdoor>(config.GetSection("Backdoors"));
     builder.Services.Configure<AuthApiParams>(config);
     builder.Services.AddAuthService(config);
     builder.Services.AddRSAPool(config.GetSection("CryptParams"));