A 42-year-old male stonemason presents to the occupational health clinic with a 6-year history of progressive dyspnea on exertion and a dry cough. He has worked in a granite quarry for the past 15 years without respiratory protective equipment. Chest X-ray shows bilateral upper lobe predominant nodular opacities with 'eggshell' calcification of hilar lymph nodes. Pulmonary function tests reveal a restrictive pattern with reduced DLCO. What is the most likely diagnosis?