Picture Prognosis

A 36-year-old healthy male presents with a 15-year history of a non-healing left foot ulcer that began after minor trauma. The lesion is erythematous with a violaceous rim, intermittently exudative, and unresponsive to antibiotics, antifungals, and steroids. He has no systemic symptoms. Biopsy shows tuberculoid granulomas with multinucleated giant cells, and Ziehl-Neelsen stain is positive for acid-fast bacilli. What’s your diagnosis?