A 28-year-old male farmer from rural Maharashtra presents to the emergency department with a 10-day history of fever, restlessness, and progressive neurological deterioration. He reports being bitten by a stray dog 6 weeks ago while working in the fields, but did not seek medical attention at that time. On examination, he is agitated, has excessive salivation, and exhibits hydrophobia—he refuses to drink water despite severe thirst. His temperature is 38.5°C, and he shows signs of autonomic instability with tachycardia (HR 110/min) and irregular respirations. CSF analysis shows lymphocytic pleocytosis with normal glucose and elevated protein. What is the most likely diagnosis?