A 2-year-old boy from rural Maharashtra is brought to the paediatric ophthalmology clinic by his mother with a complaint of white pupillary reflex (leukocoria) in the left eye noticed 3 weeks ago. On examination, the child has a white reflex in the left eye with intraocular pressure of 28 mmHg. Dilated fundoscopy reveals a white mass arising from the retina with areas of calcification. The right eye is normal. Ultrasound B-scan confirms a retinal mass with high internal reflectivity. What is the most likely diagnosis?