A 52-year-old overweight man (BMI 31 kg/m²) is newly diagnosed with type 2 diabetes after fasting plasma glucose 8.2 mmol/L and HbA1c 7.6% (60 mmol/mol). There is no significant renal or hepatic impairment and no contraindication to any oral agent. What is the most appropriate initial pharmacological management in addition to lifestyle modification?