When the upstream OpenCode process restarts, the fetch connection is
terminated by the remote side (UND_ERR_SOCKET / "other side closed").
Previously the catch block would log this as a warning and the VSCode
sseProxy would reject its run promise (sending an error to the webview)
even though the termination was normal. Now both handlers treat
UND_ERR_SOCKET the same way they treat an explicit abort.
Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>
