Melatonin for Post Tonsillectomy Emergence Agitation in Pediatric

The goal of this clinical trial is to learn if melatonin can decrease emergence agitation in pediatric post tonsillectomy. The main questions it aims to answer are: Does melatonin decrease emergence agitation in pediatric post tonsillectomy? What medical problems do participants have when taking melatonin? Researchers will compare melatonin to a placebo (a look-alike substance that contains no drug) to see if melatonin works todecrease emergence agitation in pediatric post tonsillectomy Participants will receive Oral melatonin at a dose of 0.5 mg/kg (maximum 20 mg) administered 30 minutes before induction of anesthesia. Dose chosen based on prior pediatric studies and safety data.