A 64-year-old man with a 30-pack-year smoking history presents with progressive exertional dyspnoea, chronic cough productive of sputum, and frequent winter exacerbations. Spirometry shows FEV1/FVC ratio 0.55 and FEV1 45% predicted after bronchodilator. According to current Australian COPD-X guidelines, what is the most appropriate first-line inhaled maintenance regimen (non-exacerbating eosinophil count, no asthma history)?