A 6-year-old boy from Delhi presents with a 2-week history of impetigo on his left knee following a minor abrasion. The lesions are honey-crusted and non-bullous. Culture from the purulent exudate grows β-hemolytic cocci that are Gram-positive, catalase-negative, and PYR-positive. Two weeks later, his mother reports cola-colored urine and mild ankle swelling. Urinalysis shows 2+ proteinuria, RBC casts, and dysmorphic RBCs. What is the most likely diagnosis of the renal complication?