A 32-year-old man arrives at the emergency department 2 hours after a motor vehicle collision with severe blunt chest trauma. On examination, he is tachypneic (RR 28/min), hypoxic (SpO₂ 88% on room air), and has decreased air entry bilaterally with hyperresonance on the right side. Chest X-ray confirms a right-sided pneumothorax (approximately 2 cm at the hilum) with no mediastinal shift. Vitals: BP 118/76 mmHg, HR 110/min, RR 28/min. What is the most appropriate immediate next step in management?