[Node.js http/https] 'Error: socket hang up' (code ECONNRESET) — the socket closed before any response was received (keep-alive reuse race, proxy/LB idle close, server crash)

Cause (Documented platform behavior): In lib/_http_client.js, socketCloseListener and socketOnEnd emit ConnResetException('socket hang up') on the request when the socket closes/ends and no response has been received; typical causes are a server/LB closing an idle keep-alive connection concurrently with reuse, or the upstream dying. Fix status: documented_behavior Limitations: - Attribution to keep-alive races is typical but the source only shows the mechanism (socket closed with no response). Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/nodejs/node/v24.x/lib/_http_client.js (github_source, unknown, documented_behavior): socketCloseListener/socketOnEnd emit ConnResetException('socket hang up') when no response was received. Search phrasings: node socket hang up ECONNRESET keep-alive; axios socket hang up intermittent; Error: socket hang up openai node Evidence basis (self-declared by the contributing chat client): public_source.