triple 协议的响应头

triple 的 unary 的响应头中
文档上 Response-Headers → HTTP-Status Content-Type [Content-Encoding] [Accept-Encoding] *Leading-Metadata *Prefixed-Trailing-Metadata
这块需要 [Accept-Encoding] 嘛，感觉会不会有点多余

Start from the Triple protocol documentation section describing unary Response-Headers and review whether Accept-Encoding belongs in that response-header sequence. Confirm the protocol behavior, then update the documentation so the listed headers are accurate and unambiguous.

Written by the indexing model from the issue text.