implement ship behaviors

src/lib/sim/BuildingSystem.h

@@ -10,6 +10,7 @@
 #include <vector>
 
 #include <QPoint>
+#include <QVector2D>
 
 #include "BeltSystem.h"
 #include "Building.h"
@@ -60,6 +61,16 @@ public:
     std::vector<ConstructionSite> allSites()             const;
     bool                      isTileOccupied(QPoint tile) const;
 
+    // Find nearest operational building of the given type; nullptr if none.
+    const Building* findNearestBuilding(QVector2D worldPos, BuildingType type) const;
+
+    // Place one "scrap" item into a SalvageBay's output buffer.
+    // Returns false if bay not found, wrong type, or output buffer is full.
+    bool deliverScrapToSalvageBay(EntityId bayId);
+
+    // Increase a building's HP by amount, clamped to maxHp.
+    void healBuilding(EntityId id, float amount);
+
 private:
     struct BeltEntry
     {