v4.2.7

Added

• HTTP/1 WebSocket builders support opt-in permessage-deflate negotiation through .permessage_deflate(), including RSV1 compression and decompression for negotiated data messages. Node exposes this as WebSocketBuilder.permessageDeflate(), and Python exposes it as WebSocketBuilder.permessage_deflate().

Fixed

• RFC 8441 and RFC 9220 raw WebSocket CONNECT builders allow Sec-WebSocket-Extensions negotiation metadata for caller-managed tunnel frame extensions.
• Python async RequestBuilder.body_stream().send() keeps the Rust response-body driver alive after headers return by pumping streaming body frames into a Python-owned channel, preventing Linux wheel smoke failures when iterating response.body.