A 32-year-old male farmer from Tamil Nadu presents with a 7-day history of high-grade fever, severe headache, and myalgia. He reports wading through flooded rice fields 10 days ago. On examination, he has conjunctival suffusion without exudate, a petechial rash on the trunk, and mild jaundice. His blood pressure is 100/65 mmHg. Laboratory investigations show: WBC 12,500/μL with left shift, platelets 85,000/μL, serum creatinine 2.1 mg/dL, total bilirubin 3.2 mg/dL (predominantly direct), and ALT 320 U/L. Urine dipstick shows 2+ proteinuria. What is the most likely diagnosis?