update AI and doc

core/ai/agents/base/idle_state.gd

@@ -1,5 +1,7 @@
 extends State
 
+const PATROL_STATE_ID: StringName = &"patrol"
+
 @export var wait_time: float = 3.0
 
 var runtime_timer: Timer
@@ -21,4 +23,4 @@ func exit() -> void:
 		runtime_timer = null
 
 func _on_timer_timeout() -> void:
-	transitioned.emit(self, "patrol")
+	transitioned.emit(self, PATROL_STATE_ID)