A 25-year-old male presents with hepatosplenomegaly for over 10 years, icteric sclera, occasional right hypochondriac pain, and worsening symptoms over the past 20 days (no fever). Liver is palpable 2 cm below the costal margin; spleen is enlarged 6-7 cm below the costal margin. Hemoglobin (Hb) 110 g/L, reticulocytes 20%, spherocytes 30%, WBC count 8.5×10<sup>9</sup>/L, platelets (PLT) 74×10<sup>9</sup>/L, increased RBC fragility, negative Coombs test, negative Ham test, urine urobilinogen (+), urine bilirubin (-). The diagnosis is: