split off MovementSystem and AiSystem from ShipSystem

src/lib/sim/AiSystem.h

@@ -0,0 +1,14 @@
+#pragma once
+
+class BuildingSystem;
+class ScrapSystem;
+class ShipSystem;
+
+class AiSystem
+{
+public:
+    void tickHomeReturn(ShipSystem& ships);
+    void tickThreatResponse(ShipSystem& ships, const BuildingSystem& buildings);
+    void tickRepairBehavior(ShipSystem& ships, BuildingSystem& buildings);
+    void tickScrapCollector(ShipSystem& ships, ScrapSystem& scraps, BuildingSystem& buildings);
+};