update AI and doc

core/ai/agents/base/patrol_state.gd

@@ -1,10 +1,12 @@
 extends State
 
+const IDLE_STATE_ID: StringName = &"idle"
+
 @onready var agent: AIBase = owner
 
 func enter() -> void:
 	agent.navigate_to_random_point()
 
-func update(_delta)  -> void:
+func physics_update(_delta)  -> void:
 	if agent.nav_agent.is_navigation_finished():
-		transitioned.emit(self, "idle")
+		transitioned.emit(self, IDLE_STATE_ID)