refactor(backend): align station module production semantics

apps/backend/Stations/Runtime/StationRuntimeModels.cs

@@ -65,6 +65,14 @@ public class StationModuleRuntime
               Health = production.Hull,
               MaxHealth = production.Hull,
           },
+          BuildModuleDefinition build => new BuildStationModuleRuntime
+          {
+              Id = id,
+              ModuleId = build.Id,
+              ModuleType = build.ModuleType,
+              Health = build.Hull,
+              MaxHealth = build.Hull,
+          },
           _ => new StationModuleRuntime
           {
               Id = id,
@@ -81,6 +89,10 @@ public sealed class ProductionStationModuleRuntime : StationModuleRuntime
     public IReadOnlyList<string> ProductItemIds { get; init; } = [];
 }
 
+public sealed class BuildStationModuleRuntime : StationModuleRuntime
+{
+}
+
 public sealed class StorageStationModuleRuntime : StationModuleRuntime
 {
     public StorageKind StorageKind { get; init; }