make construction its own system (extracted from BuildingSystem)

src/test/BehaviorSystemTest.cpp

@@ -15,6 +15,7 @@
 #include "BeltSystem.h"
 #include "Building.h"
 #include "BuildingSystem.h"
+#include "ConstructionSystem.h"
 #include "FactoryState.h"
 #include "BuildingType.h"
 #include "ConfigLoader.h"
@@ -63,6 +64,7 @@ struct Fixture
     std::mt19937   rng;
     EntityAdmin    admin;
     BuildingSystem buildings;
+    ConstructionSystem construction;
     ShipSystem     ships;
     AiSystem             ai;
     SalvagerSystem       salvager;
@@ -85,6 +87,7 @@ struct Fixture
                     [](const std::string&, QVector2D, const std::optional<ShipLayoutConfig>&) {},
                     [](const std::string&) -> bool { return true; },
                     rng)
+        , construction(cfg)
         , ships(cfg, admin)
         , ai(cfg)
         , salvager(admin)
@@ -957,7 +960,7 @@ TEST_CASE("BehaviorSystem: full-cargo salvage ship moves toward SalvageBay", "[b
     Tick t = 0;
     for (int i = 0; i < 500; ++i)
     {
-        f.buildings.tickConstruction(f.state, t++);
+        f.construction.tick(f.state, f.belts, t++);
         if (findBuilding(f.state, bayId) != nullptr)
         {
             break;
@@ -992,7 +995,7 @@ TEST_CASE("SalvagerSystem: full-cargo ship at its SalvageBay hands over cargo",
     Tick t = 0;
     for (int i = 0; i < 500; ++i)
     {
-        f.buildings.tickConstruction(f.state, t++);
+        f.construction.tick(f.state, f.belts, t++);
         if (findBuilding(f.state, bayId) != nullptr) { break; }
     }
     const Building* bay = findBuilding(f.state, bayId);