diff --git a/src/test/CombatSystemTest.cpp b/src/test/CombatSystemTest.cpp
index 2c5917e..a1a82b6 100644
--- a/src/test/CombatSystemTest.cpp
+++ b/src/test/CombatSystemTest.cpp
@@ -194,8 +194,7 @@ TEST_CASE("CombatSystem: no fire when target is out of range", "[combat]")
 
 TEST_CASE("CombatSystem: player station fires at enemy ship in range", "[combat]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     // Find the player defence station.
     EntityId stationId = kInvalidEntityId;
@@ -223,7 +222,7 @@ TEST_CASE("CombatSystem: player station fires at enemy ship in range", "[combat]
     }
 
     // Find a combat ship blueprint for the enemy.
-    const ShipDef* combatDef = findCombatShip(cfg);
+    const ShipDef* combatDef = findCombatShip(sim.config());
     REQUIRE(combatDef != nullptr);
 
     const EntityId enemyId = sim.ships().spawn(
@@ -246,8 +245,7 @@ TEST_CASE("CombatSystem: player station fires at enemy ship in range", "[combat]
 
 TEST_CASE("CombatSystem: enemy station fires at player ship in range", "[combat]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     // Find the enemy defence station.
     EntityId stationId = kInvalidEntityId;
@@ -265,7 +263,7 @@ TEST_CASE("CombatSystem: enemy station fires at player ship in range", "[combat]
     }
     REQUIRE(stationId != kInvalidEntityId);
 
-    const ShipDef* combatDef = findCombatShip(cfg);
+    const ShipDef* combatDef = findCombatShip(sim.config());
     REQUIRE(combatDef != nullptr);
 
     // Spawn a player ship right next to the enemy station.
@@ -291,10 +289,9 @@ TEST_CASE("CombatSystem: enemy station fires at player ship in range", "[combat]
 
 TEST_CASE("CombatSystem: dead ship is removed after tick step 9", "[combat]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
-    const ShipDef* combatDef = findCombatShip(cfg);
+    const ShipDef* combatDef = findCombatShip(sim.config());
     REQUIRE(combatDef != nullptr);
 
     const EntityId shipId = sim.ships().spawn(combatDef->id, 1,
@@ -310,12 +307,11 @@ TEST_CASE("CombatSystem: dead ship is removed after tick step 9", "[combat]")
 
 TEST_CASE("CombatSystem: scrap is spawned on ship death", "[combat]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     // Find a ship def that drops scrap.
     const ShipDef* droppingDef = nullptr;
-    for (const ShipDef& def : cfg.ships.ships)
+    for (const ShipDef& def : sim.config().ships.ships)
     {
         if (def.loot.scrapDrop > 0)
         {
@@ -337,8 +333,7 @@ TEST_CASE("CombatSystem: scrap is spawned on ship death", "[combat]")
 
 TEST_CASE("CombatSystem: HQ death sets game over", "[combat]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     sim.buildings().forEachBuilding([](Building& b)
     {
diff --git a/src/test/ShipyardTest.cpp b/src/test/ShipyardTest.cpp
index a24f9d5..d4e691a 100644
--- a/src/test/ShipyardTest.cpp
+++ b/src/test/ShipyardTest.cpp
@@ -73,12 +73,11 @@ static void fillMaterials(Simulation& sim, EntityId yardId, const ShipDef& def)
 TEST_CASE("Shipyard: spawns a player ship after production cycle completes",
           "[shipyard]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
-    const ShipDef* def = findAvailableBlueprint(cfg);
+    const ShipDef* def = findAvailableBlueprint(sim.config());
     REQUIRE(def != nullptr);
-    const BuildingDef* yardDef = findShipyardDef(cfg);
+    const BuildingDef* yardDef = findShipyardDef(sim.config());
     REQUIRE(yardDef != nullptr);
 
     const int shipsBefore = static_cast<int>(sim.ships().allShips().size());
@@ -119,10 +118,9 @@ TEST_CASE("Shipyard: spawns a player ship after production cycle completes",
 
 TEST_CASE("Shipyard: does not spawn without a blueprint set", "[shipyard]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
-    const BuildingDef* yardDef = findShipyardDef(cfg);
+    const BuildingDef* yardDef = findShipyardDef(sim.config());
     REQUIRE(yardDef != nullptr);
 
     const int shipsBefore = static_cast<int>(sim.ships().allShips().size());
@@ -136,12 +134,11 @@ TEST_CASE("Shipyard: does not spawn without a blueprint set", "[shipyard]")
 
 TEST_CASE("Shipyard: does not spawn with insufficient materials", "[shipyard]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
-    const ShipDef* def = findAvailableBlueprint(cfg);
+    const ShipDef* def = findAvailableBlueprint(sim.config());
     REQUIRE(def != nullptr);
-    const BuildingDef* yardDef = findShipyardDef(cfg);
+    const BuildingDef* yardDef = findShipyardDef(sim.config());
     REQUIRE(yardDef != nullptr);
 
     const int shipsBefore = static_cast<int>(sim.ships().allShips().size());
@@ -161,12 +158,11 @@ TEST_CASE("Shipyard: does not spawn with insufficient materials", "[shipyard]")
 
 TEST_CASE("Shipyard: spawns a second ship after materials replenished", "[shipyard]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
-    const ShipDef* def = findAvailableBlueprint(cfg);
+    const ShipDef* def = findAvailableBlueprint(sim.config());
     REQUIRE(def != nullptr);
-    const BuildingDef* yardDef = findShipyardDef(cfg);
+    const BuildingDef* yardDef = findShipyardDef(sim.config());
     REQUIRE(yardDef != nullptr);
 
     const EntityId yardId = placeShipyard(sim, *yardDef);
diff --git a/src/test/SimulationTest.cpp b/src/test/SimulationTest.cpp
index dd7fc2c..c3644c0 100644
--- a/src/test/SimulationTest.cpp
+++ b/src/test/SimulationTest.cpp
@@ -17,16 +17,14 @@ static GameConfig loadConfig()
 
 TEST_CASE("Simulation::currentTick starts at 0", "[simulation]")
 {
-    const GameConfig config = loadConfig();
-    const Simulation sim(config);
+    const Simulation sim(loadConfig());
 
     REQUIRE(sim.currentTick() == 0);
 }
 
 TEST_CASE("Simulation::tick increments currentTick by 1", "[simulation]")
 {
-    const GameConfig config = loadConfig();
-    Simulation sim(config);
+    Simulation sim(loadConfig());
 
     sim.tick();
 
@@ -35,8 +33,7 @@ TEST_CASE("Simulation::tick increments currentTick by 1", "[simulation]")
 
 TEST_CASE("Simulation::tick 10 times yields currentTick == 10", "[simulation]")
 {
-    const GameConfig config = loadConfig();
-    Simulation sim(config);
+    Simulation sim(loadConfig());
 
     for (int i = 0; i < 10; ++i)
     {
@@ -48,16 +45,14 @@ TEST_CASE("Simulation::tick 10 times yields currentTick == 10", "[simulation]")
 
 TEST_CASE("Simulation::drainFireEvents returns empty initially", "[simulation]")
 {
-    const GameConfig config = loadConfig();
-    Simulation sim(config);
+    Simulation sim(loadConfig());
 
     REQUIRE(sim.drainFireEvents().empty());
 }
 
 TEST_CASE("Simulation::drainFireEvents clears queue on drain", "[simulation]")
 {
-    const GameConfig config = loadConfig();
-    Simulation sim(config);
+    Simulation sim(loadConfig());
 
     // First drain: empty.
     sim.drainFireEvents();
@@ -68,8 +63,7 @@ TEST_CASE("Simulation::drainFireEvents clears queue on drain", "[simulation]")
 
 TEST_CASE("Simulation::drainBlueprintDropEvents returns empty initially", "[simulation]")
 {
-    const GameConfig config = loadConfig();
-    Simulation sim(config);
+    Simulation sim(loadConfig());
 
     REQUIRE(sim.drainBlueprintDropEvents().empty());
 }
diff --git a/src/test/WaveSystemTest.cpp b/src/test/WaveSystemTest.cpp
index ad4ca76..ae3f046 100644
--- a/src/test/WaveSystemTest.cpp
+++ b/src/test/WaveSystemTest.cpp
@@ -98,8 +98,7 @@ TEST_CASE("WaveSystem: generation starts at 0 and increments on push", "[wave]")
 
 TEST_CASE("WaveSystem: Simulation pre-places HQ + 2 player + 2 enemy stations", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    const Simulation sim(cfg, 42);
+    const Simulation sim(loadConfig(), 42);
 
     int hqCount      = 0;
     int playerCount  = 0;
@@ -118,11 +117,10 @@ TEST_CASE("WaveSystem: Simulation pre-places HQ + 2 player + 2 enemy stations",
 
 TEST_CASE("WaveSystem: HQ has correct initial HP from config", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    const Simulation sim(cfg, 42);
+    const Simulation sim(loadConfig(), 42);
 
     const float expectedHp =
-        static_cast<float>(cfg.stations.hq.hpFormula.evaluate(0.0));
+        static_cast<float>(sim.config().stations.hq.hpFormula.evaluate(0.0));
     bool found = false;
     float actualHp = 0.0f;
     for (const Building& b : sim.buildings().allBuildings())
@@ -141,8 +139,7 @@ TEST_CASE("WaveSystem: HQ has correct initial HP from config", "[wave]")
 
 TEST_CASE("WaveSystem: HQ anchor is at asteroid right edge", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    const Simulation sim(cfg, 42);
+    const Simulation sim(loadConfig(), 42);
 
     for (const Building& b : sim.buildings().allBuildings())
     {
@@ -159,8 +156,7 @@ TEST_CASE("WaveSystem: HQ anchor is at asteroid right edge", "[wave]")
 
 TEST_CASE("WaveSystem: player stations have weapon set", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    const Simulation sim(cfg, 42);
+    const Simulation sim(loadConfig(), 42);
 
     int armedPlayerStations = 0;
     for (const Building& b : sim.buildings().allBuildings())
@@ -178,8 +174,7 @@ TEST_CASE("WaveSystem: player stations have weapon set", "[wave]")
 
 TEST_CASE("WaveSystem: enemy stations have weapon set", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    const Simulation sim(cfg, 42);
+    const Simulation sim(loadConfig(), 42);
 
     int armedEnemyStations = 0;
     for (const Building& b : sim.buildings().allBuildings())
@@ -201,8 +196,7 @@ TEST_CASE("WaveSystem: enemy stations have weapon set", "[wave]")
 
 TEST_CASE("WaveSystem: enemy ships spawn after the initial gap elapses", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     // The maximum gap is gapMaxSeconds = 45s → 1350 ticks.
     // Run 1500 ticks to guarantee at least one wave has triggered.
@@ -226,8 +220,7 @@ TEST_CASE("WaveSystem: enemy ships spawn after the initial gap elapses", "[wave]
 
 TEST_CASE("WaveSystem: only eligible ships (cost > 0) appear in waves", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     // Run long enough for several waves.
     const int limit = static_cast<int>(secondsToTicks(120.0));
@@ -251,8 +244,7 @@ TEST_CASE("WaveSystem: only eligible ships (cost > 0) appear in waves", "[wave]"
 
 TEST_CASE("WaveSystem: destroying both enemy stations triggers a push", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     // Damage both enemy stations to 0.
     sim.buildings().forEachBuilding([](Building& b)
@@ -276,8 +268,7 @@ TEST_CASE("WaveSystem: destroying both enemy stations triggers a push", "[wave]"
 
 TEST_CASE("WaveSystem: push emits exactly one BlueprintDropEvent", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     sim.buildings().forEachBuilding([](Building& b)
     {
@@ -295,8 +286,7 @@ TEST_CASE("WaveSystem: push emits exactly one BlueprintDropEvent", "[wave]")
 
 TEST_CASE("WaveSystem: push blueprint drop awards a known ship id", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     sim.buildings().forEachBuilding([](Building& b)
     {
@@ -311,7 +301,7 @@ TEST_CASE("WaveSystem: push blueprint drop awards a known ship id", "[wave]")
     REQUIRE(events.size() == 1);
 
     bool validId = false;
-    for (const ShipDef& def : cfg.ships.ships)
+    for (const ShipDef& def : sim.config().ships.ships)
     {
         if (def.id == events[0].blueprintId)
         {
@@ -325,8 +315,7 @@ TEST_CASE("WaveSystem: push blueprint drop awards a known ship id", "[wave]")
 
 TEST_CASE("WaveSystem: push places new enemy stations further right", "[wave]")
 {
-    const GameConfig cfg = loadConfig();
-    Simulation sim(cfg, 42);
+    Simulation sim(loadConfig(), 42);
 
     // Record the X position of the initial enemy stations.
     int initialX = std::numeric_limits<int>::min();