refactor AI system

src/lib/ecs/system/ai/AttackExecutor.h

@@ -0,0 +1,12 @@
+#pragma once
+
+class EntityAdmin;
+
+// When Attack wins, moves the ship toward its target and assigns that target to
+// each weapon that has it in range. Weapons whose range excludes the target are
+// left untouched so CombatSystem can keep/acquire a closer target (no thrash).
+class AttackExecutor
+{
+public:
+    void execute(EntityAdmin& admin);
+};