A 68-year-old woman from Delhi presents with a 10-month history of a dark nodular lesion on her right calf. She reports recent bleeding and crusting. On examination, the lesion is 12 mm in diameter, dark brown-black, with a firm nodular consistency and surface ulceration. Histopathology shows invasive melanoma with Breslow thickness of 4.2 mm, ulceration present, 8 mitoses per mm², and Clark level IV invasion. Sentinel lymph node biopsy shows micrometastases in 1 of 2 right inguinal lymph nodes (tumor burden <0.1 mm). No distant metastases are detected on staging imaging. According to AJCC 8th edition, what is the stage of this melanoma?