implement ships depart in waves

src/lib/sim/ShipSystem.h

@@ -47,6 +47,12 @@ public:
     // -- Movement (tick-order step 10) ---------------------------------------
     void tickMovement();
 
+    // Set the rally point that newly spawned player combat ships will loiter at.
+    void setRallyPoint(QVector2D point);
+
+    // Release all gathered player combat ships to advance toward the enemy.
+    void triggerRallyDeparture();
+
     // Reduce ship HP by amount. Does not remove the ship; step 9 handles death.
     // Returns false if ship not found.
     bool damageShip(EntityId id, float amount);
@@ -66,4 +72,5 @@ private:
     const GameConfig&         m_config;
     std::function<EntityId()> m_allocateId;
     std::vector<Ship>         m_ships;
+    QVector2D                 m_rallyPoint;
 };