Refactor world bootstrap and allow empty startup worlds

apps/backend/Simulation/Core/SimulationEngine.cs

@@ -1,7 +1,8 @@
 namespace SpaceGame.Api.Simulation.Core;
 
-public sealed class SimulationEngine
+internal sealed class SimulationEngine
 {
+    private readonly IBalanceService _balance;
     private readonly OrbitalSimulationOptions _orbitalSimulation;
     private readonly OrbitalStateUpdater _orbitalStateUpdater;
     private readonly InfrastructureSimulationService _infrastructureSimulation;
@@ -13,9 +14,10 @@ public sealed class SimulationEngine
     private readonly ShipAiService _shipAi;
     private readonly SimulationProjectionService _projection;
 
-    public SimulationEngine(OrbitalSimulationOptions? orbitalSimulation = null)
+    internal SimulationEngine(OrbitalSimulationOptions orbitalSimulation, IBalanceService balance)
     {
-        _orbitalSimulation = orbitalSimulation ?? new OrbitalSimulationOptions();
+        _balance = balance;
+        _orbitalSimulation = orbitalSimulation;
         _orbitalStateUpdater = new OrbitalStateUpdater(_orbitalSimulation);
         _infrastructureSimulation = new InfrastructureSimulationService();
         _geopolitics = new GeopoliticalSimulationService();
@@ -23,7 +25,7 @@ public sealed class SimulationEngine
         _playerFaction = new PlayerFactionService();
         _stationSimulation = new StationSimulationService();
         _stationLifecycle = new StationLifecycleService(_stationSimulation);
-        _shipAi = new ShipAiService();
+        _shipAi = new ShipAiService(balance);
         _projection = new SimulationProjectionService(_orbitalSimulation);
     }
 
@@ -31,7 +33,7 @@ public sealed class SimulationEngine
     {
         var nowUtc = DateTimeOffset.UtcNow;
         var events = new List<SimulationEventRecord>();
-        var simulationDeltaSeconds = deltaSeconds * MathF.Max(world.Balance.SimulationSpeedMultiplier, 0.01f);
+        var simulationDeltaSeconds = deltaSeconds * MathF.Max(_balance.SimulationSpeedMultiplier, 0.01f);
         world.GeneratedAtUtc = nowUtc;
 
         world.OrbitalTimeSeconds += simulationDeltaSeconds * _orbitalSimulation.SimulatedSecondsPerRealSecond;