Add settings endpoints and registration status check: implement new API endpoints for settings management, including registration status retrieval, and update the registration command handler to enforce registration rules based on site settings.

backend/src/TeleWave.Api/Endpoints/SettingsEndpoints.cs

@@ -0,0 +1,44 @@
+using LiteCqrs;
+using TeleWave.Api.Common;
+using TeleWave.Application.Settings;
+using TeleWave.Application.Settings.GetSiteSettings;
+using TeleWave.Application.Settings.UpdateSiteSettings;
+using TeleWave.Infrastructure.Identity;
+
+namespace TeleWave.Api.Endpoints;
+
+public static class SettingsEndpoints
+{
+    public static IEndpointRouteBuilder MapSettingsEndpoints(this IEndpointRouteBuilder app)
+    {
+        var admin = app.MapGroup("/api/admin/settings")
+            .WithTags("Admin.Settings")
+            .RequireAuthorization(policy => policy.RequireRole(RoleNames.Admin));
+
+        admin.MapGet("", GetSettings).Produces<SiteSettingsDto>();
+        admin.MapPut("", UpdateSettings).Produces(StatusCodes.Status204NoContent);
+
+        return app;
+    }
+
+    private static async Task<IResult> GetSettings(ISender sender, CancellationToken cancellationToken)
+    {
+        var settings = await sender.Send(new GetSiteSettingsQuery(), cancellationToken);
+        return Results.Ok(settings);
+    }
+
+    private static async Task<IResult> UpdateSettings(
+        UpdateSiteSettingsBody body,
+        ISender sender,
+        CancellationToken cancellationToken
+    )
+    {
+        var result = await sender.Send(
+            new UpdateSiteSettingsCommand(body.RegistrationEnabled),
+            cancellationToken
+        );
+        return result.ToHttpResult();
+    }
+}
+
+public sealed record UpdateSiteSettingsBody(bool RegistrationEnabled);