show threat rate in debug output

src/lib/sim/BuildingSystem.cpp

@@ -867,6 +867,44 @@ std::vector<ConstructionSite> BuildingSystem::allSites() const
                                          m_constructionQueue.end());
 }
 
+namespace
+{
+bool isProductionBuildingType(BuildingType type)
+{
+    switch (type)
+    {
+    case BuildingType::Miner:
+    case BuildingType::Smelter:
+    case BuildingType::Assembler:
+    case BuildingType::ReprocessingPlant:
+    case BuildingType::Shipyard:
+        return true;
+    default:
+        return false;
+    }
+}
+}  // namespace
+
+int BuildingSystem::productionBuildingCount() const
+{
+    int count = 0;
+    for (const Building& b : m_buildings)
+    {
+        if (isProductionBuildingType(b.type)) { ++count; }
+    }
+    return count;
+}
+
+int BuildingSystem::activeProductionBuildingCount() const
+{
+    int count = 0;
+    for (const Building& b : m_buildings)
+    {
+        if (isProductionBuildingType(b.type) && b.production.has_value()) { ++count; }
+    }
+    return count;
+}
+
 std::vector<BuildingSystem::BeltTileInfo> BuildingSystem::allBeltTiles() const
 {
     std::vector<BeltTileInfo> result;