A 42-year-old woman is brought to the trauma bay after a fall from a 15-foot scaffold. On primary survey: GCS 14 (opens eyes to pain, confused speech, withdraws from pain), airway patent with cervical spine precautions in place, respiratory rate 28/min, oxygen saturation 94% on room air, heart rate 118/min, blood pressure 102/68 mmHg. Breath sounds are diminished on the right side. On secondary survey, you note right-sided rib fractures (ribs 5–8), right flank ecchymosis, and abdominal distension. What is the most critical finding on primary survey that requires immediate intervention?