Refactor world bootstrap and allow empty startup worlds

apps/backend/Universe/Scenario/LoaderSupport.cs

@@ -5,7 +5,6 @@ namespace SpaceGame.Api.Universe.Scenario;
 
 internal static class LoaderSupport
 {
-    internal const string DefaultFactionId = "sol-dominion";
     internal const float MinimumFactionCredits = 0f;
     internal const float MinimumRefineryOre = 0f;
     internal const float MinimumRefineryStock = 0f;
@@ -97,7 +96,7 @@ internal static class LoaderSupport
     {
         if (!moduleDefinitions.TryGetValue(moduleId, out var definition))
         {
-            return;
+            throw new InvalidOperationException($"Module '{moduleId}' is not defined in static data.");
         }
 
         station.Modules.Add(StationModuleRuntime.Create($"{station.Id}-module-{station.Modules.Count + 1}", definition));