A 35-year-old woman from coastal Odisha presents with progressive fatigue, dyspnea, and jaundice for 4 weeks. She has a history of multiple blood transfusions 6 months ago. On examination, she has moderate hepatosplenomegaly and mild pallor. Hemoglobin is 7.2 g/dL with reticulocytosis. Peripheral blood smear shows crescent-shaped gametocytes within RBCs and occasional mature schizonts with 8–12 merozoites. What is the most likely diagnosis?