A 32-year-old woman from Mumbai presents with a 4-month history of a generalized maculopapular rash involving the trunk and extremities, including the palms and soles. She also reports oral ulcers (mucous patches), low-grade fever, and generalized lymphadenopathy. She recalls a painless genital ulcer 2 months ago that healed spontaneously. Serology shows positive RPR (1:16) and positive FTA-ABS. What is the most likely stage of syphilis?