Long local-LLM SSE streams (e.g. vLLM buffering large tool calls) exceeded
undici's default 300s bodyTimeout and aborted with UND_ERR_BODY_TIMEOUT.
retry.provider.timeoutMs cannot lift this cap because it controls the
provider SDK's AbortController deadline, not undici's per-socket idle timer.
Pass { bodyTimeout: 0, headersTimeout: 0 } to EnvHttpProxyAgent. Provider
SDKs still enforce their own timeouts via retry.provider.timeoutMs.
closes#3715
ea90a6783d