ksys/act: Add ActorSystem stub

src/KingSystem/ActorSystem/actActorSystem.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <heap/seadDisposer.h>
+
+namespace ksys::act {
+
+// TODO: incomplete
+class ActorSystem {
+    SEAD_SINGLETON_DISPOSER(ActorSystem)
+    ActorSystem();
+
+public:
+    void onBaseProcMgrCalc();
+};
+
+}  // namespace ksys::act