Refactor world bootstrap and allow empty startup worlds

apps/backend/Universe/Simulation/IBalanceService.cs

@@ -0,0 +1,16 @@
+namespace SpaceGame.Api.Universe.Simulation;
+
+public interface IBalanceService
+{
+    float SimulationSpeedMultiplier { get; }
+    float YPlane { get; }
+    float ArrivalThreshold { get; }
+    float MiningRate { get; }
+    float MiningCycleSeconds { get; }
+    float TransferRate { get; }
+    float DockingDuration { get; }
+    float UndockingDuration { get; }
+    float UndockDistance { get; }
+    BalanceOptions GetCurrent();
+    BalanceOptions Update(BalanceOptions candidate);
+}