A 38-year-old male, HBsAg(+) for 5 years, with recurrent ALT elevations over the past 2 years (resolved after treatment). For the past 2 months, he reports fatigue and poor appetite. Exam: no scleral icterus, no palmar erythema or spider angiomas, liver palpable 1 cm below costal margin, spleen palpable laterally. ALT 420 IU/L, TbiL 20 μmol/L, HBsAg(+). The most likely diagnosis is: