Implement surface safety and powered props

src/ReactorMaintenance.Simulation/SimulationEngine.cs

@@ -51,6 +51,9 @@ public sealed class SimulationEngine
 
     public IReadOnlyList<Forecast> Forecast(LevelState level)
     {
+        if (!level.HasActivePoweredTerminalAccess())
+            return Array.Empty<Forecast>();
+
         return ForecastSystem.Forecast(level, simulated => ResolveStep(simulated, false));
     }