add balancing tool target

src/balancing/ArenaSimulation.h

@@ -0,0 +1,84 @@
+#pragma once
+
+#include <atomic>
+#include <memory>
+#include <mutex>
+#include <random>
+#include <string>
+#include <vector>
+
+#include "BalancingConfig.h"
+#include "BeltSystem.h"
+#include "EntityId.h"
+#include "FireEvent.h"
+#include "GameConfig.h"
+#include "Tick.h"
+
+class BuildingSystem;
+class CombatSystem;
+class ShipSystem;
+class ScrapSystem;
+
+struct ArenaStatus
+{
+    struct Entry
+    {
+        std::string displayName;
+        int level;
+        int total;
+        int surviving;
+    };
+
+    struct TeamStatus
+    {
+        std::string name;
+        std::vector<Entry> entries;  // HQ first, then ships, then stations
+    };
+
+    TeamStatus teams[2];
+    bool finished = false;
+};
+
+class ArenaSimulation
+{
+public:
+    ArenaSimulation(const GameConfig& gameConfig,
+                    ArenaConfig arenaConfig,
+                    unsigned int seed = 0);
+    ~ArenaSimulation();
+
+    void run();
+    void requestStop();
+
+    ArenaStatus status() const;
+
+private:
+    EntityId allocateId();
+    void placeStructures();
+    void spawnShips();
+    void tick();
+    void tickDeaths();
+    void updateStatus();
+
+    const GameConfig& m_gameConfig;
+    ArenaConfig m_arenaConfig;
+    std::mt19937 m_rng;
+
+    Tick m_currentTick;
+    EntityId m_nextId;
+
+    BeltSystem m_beltSystem;
+    std::unique_ptr<BuildingSystem> m_buildingSystem;
+    std::unique_ptr<ShipSystem> m_shipSystem;
+    std::unique_ptr<CombatSystem> m_combatSystem;
+    std::unique_ptr<ScrapSystem> m_scrapSystem;
+
+    EntityId m_team1HqId;
+    EntityId m_team2HqId;
+
+    bool m_finished;
+    std::atomic<bool> m_stopRequested;
+
+    mutable std::mutex m_statusMutex;
+    ArenaStatus m_status;
+};