A 62-year-old man with a 40-pack-year smoking history presents with progressive dyspnea on exertion and chronic productive cough with copious purulent sputum for the past 8 years. On examination, he has cyanosis, barrel chest, and prominent use of accessory muscles. Spirometry shows FEV₁/FVC ratio of 0.58 with minimal bronchodilator response. High-resolution CT chest reveals bronchial wall thickening, bronchus-to-artery ratio >1, and lack of distal alveolar destruction. Which pathological process best explains his clinical and radiological findings?