A 28-year-old woman from Delhi presents with irregular menstrual cycles for the past 3 years. She reports oligomenorrhea (cycles ranging from 45 to 90 days), excessive facial hair, and acne. On examination, she has a BMI of 32 kg/m², hirsutism (Ferriman–Gallwey score 18), and acanthosis nigricans on the neck. Pelvic ultrasound shows bilateral ovarian cysts (>10 mm) with increased stromal echogenicity. Fasting blood glucose is 105 mg/dL. LH:FSH ratio is 3.2:1. What is the most appropriate first-line pharmacological intervention for her menstrual irregularity and hyperandrogenism?