Add circle timer

scripts/oven/state/cooking.gd

@@ -17,9 +17,10 @@ func enter_from(state):
 
 	ctx.get_node("cook_timer").start()
 	ctx.get_node("status_light").activate()
+	ctx.get_node("circle_timer").set_timer(ctx.get_node("cook_timer"))
 
 func exit_to(state):
-	pass
+	ctx.get_node("circle_timer").clear_timer()
 
 func on_coin_machine_coin_requirement_met(player):
 	assert(false, "coin machine should be disabled while growing")