The Docker client SDK v28.5.2 defaults to API version 1.51, which may not
be supported by older Docker daemon versions. Although WithAPIVersionNegotiation()
is used, the manual Ping() call in initClient() does not trigger the automatic
version negotiation flow.
This fix explicitly calls NegotiateAPIVersionPing() with the ping response
to ensure the client uses a compatible API version with the Docker daemon.
This resolves the '404 Not Found for API route and version' error when
controlling Nginx in another Docker container.
Fixes#1543
Co-authored-by: Cursor Agent <cursoragent@cursor.com>
