GET /files/{id}
  status=200 body=ABCDEFGHIJKLMNOPQRSTUVWXYZ
  content-type: application/octet-stream
  content-length: 26
  content-disposition: attachment; filename="resume 2026.txt"; filename*=UTF-8''r%C3%A9sum%C3%A9%202026.txt
  accept-ranges: bytes
  x-content-type-options: nosniff
GET /files/{id} with Range: bytes=10-19
  status=206 body=KLMNOPQRST
  content-range: bytes 10-19/26
GET /files/{id} with Range: bytes=500-
  status=416 content-range: bytes */26