feat(backend): move endpoints to FastEndpoints handlers

apps/backend/Handlers/RootRedirectHandler.cs

@@ -0,0 +1,18 @@
+using FastEndpoints;
+
+namespace SpaceGame.Simulation.Api.Handlers;
+
+public sealed class RootRedirectHandler : EndpointWithoutRequest
+{
+  public override void Configure()
+  {
+    Get("/");
+    AllowAnonymous();
+  }
+
+  public override Task HandleAsync(CancellationToken cancellationToken)
+  {
+    HttpContext.Response.Redirect("/api/world");
+    return Task.CompletedTask;
+  }
+}