improvement on gm windows, ai

apps/backend/Universe/Api/UpdateBalanceHandler.cs

@@ -0,0 +1,20 @@
+using FastEndpoints;
+using SpaceGame.Api.Definitions;
+using SpaceGame.Api.Universe.Simulation;
+
+namespace SpaceGame.Api.Universe.Api;
+
+public sealed class UpdateBalanceHandler(WorldService worldService) : Endpoint<BalanceDefinition>
+{
+  public override void Configure()
+  {
+    Put("/api/balance");
+    AllowAnonymous();
+  }
+
+  public override Task HandleAsync(BalanceDefinition req, CancellationToken cancellationToken)
+  {
+    var applied = worldService.UpdateBalance(req);
+    return SendOkAsync(applied, cancellationToken);
+  }
+}