implement load config on game restart

src/lib/sim/Simulation.h

@@ -26,12 +26,17 @@ class WaveSystem;
 class Simulation
 {
 public:
-    explicit Simulation(const GameConfig& config, unsigned int seed = 0);
+    explicit Simulation(GameConfig config, unsigned int seed = 0);
     ~Simulation();
 
+    const GameConfig& config() const;
+
     // Reinitializes all simulation state as if constructed fresh.
     void reset(unsigned int seed = 0);
 
+    // Reloads config then reinitializes all simulation state.
+    void reset(GameConfig newConfig, unsigned int seed = 0);
+
     // Advances the simulation by one tick. Tick order per architecture.md §Tick Order.
     void tick();
 
@@ -83,7 +88,7 @@ private:
     // Award a random blueprint drop (REQ-DEF-BLUEPRINT-DROP) and emit the event.
     void awardBlueprintDrop();
 
-    const GameConfig& m_config;
+    GameConfig m_config;
     std::mt19937 m_rng;
 
     Tick     m_currentTick;