Function encode_response 

fn encode_response<T: Serialize>(headers: &HeaderMap, value: T) -> Response

Encode a successful response body based on the request’s Accept header, matching tide-disco’s content negotiation.

surf-disco’s default Accept is application/octet-stream, so production internal clients (peer-catchup, submit-transactions, light-client provider) expect VBS-encoded responses for the endpoints that flow large structured data. Falls back to JSON otherwise.