refactor AI system

src/lib/ecs/system/RepairSystem.h

@@ -0,0 +1,17 @@
+#pragma once
+
+class EntityAdmin;
+
+// World-mutation system for repair modules: validates each tool's target (set by
+// RepairExecutor), falls back to the nearest damaged friendly in range, and
+// applies healing. Runs every tick, independent of behavior selection.
+class RepairSystem
+{
+public:
+    explicit RepairSystem(EntityAdmin& admin);
+
+    void tick();
+
+private:
+    EntityAdmin& m_admin;
+};