A 28-year-old Indian woman presents with severe dyspareunia and infertility of 2 years duration. She reports cyclic pelvic pain that is worse during menstruation and radiates to the lower back. On examination, the uterus is normal-sized and mobile. Transvaginal ultrasound reveals a 4 cm left ovarian cyst with internal echoes and a retroverted uterus with peritoneal adhesions. Diagnostic laparoscopy shows multiple peritoneal implants, chocolate cysts on both ovaries, and dense adhesions involving the bowel. What is the most likely diagnosis?