Edison Jwa
6c380fc7db
feat(protocol): add file download support for avatars and icons
- Add Request::DownloadFile variant with oneshot reply
- Add ProtocolClient::download_avatar(client_uid) and download_icon(icon_id)
- Track pending file downloads by FiletransferHandle
- Handle StreamItem::FileDownload: read bytes from TCP stream
- Handle StreamItem::FiletransferFailed: map to ProtocolError
- Add ProtocolError::FileTransfer(String) variant
- Add path helper tests for avatar/icon download paths
- No tsclientlib types leak across the adapter boundary