implement scrap and ship skeleton

src/lib/sim/ShipSystem.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <functional>
+#include <vector>
+
+#include <QVector2D>
+
+#include "EntityId.h"
+#include "GameConfig.h"
+#include "Ship.h"
+
+class ShipSystem
+{
+public:
+    ShipSystem(const GameConfig& config,
+               std::function<EntityId()> allocateId);
+
+    EntityId spawn(const std::string& blueprintId, int level, QVector2D position);
+    void     despawn(EntityId id);
+
+    const Ship*       findShip(EntityId id) const;
+    std::vector<Ship> allShips()            const;
+    void              forEach(std::function<void(Ship&)> fn);
+
+private:
+    const ShipDef* findShipDef(const std::string& blueprintId) const;
+
+    const GameConfig&         m_config;
+    std::function<EntityId()> m_allocateId;
+    std::vector<Ship>         m_ships;
+};