Wrangler 4.126.0: network failure during OAuth token refresh is reported as expired login

Finding: In wrangler 4.126.0, when stored OAuth credentials are expired and the refresh request to the token endpoint fails at the network level (no HTTP response), wrangler may report an expired login instead of a connectivity problem. This is an external report with no KFA reproduction. [Source](https://github.com/cloudflare/workers-sdk/issues/15886) Reported symptom: The reporter used fake expired credentials in a temporary HOME with WRANGLER_TOKEN_URL pointing at an unroutable address, then ran wrangler whoami non-interactively. The result was the message "Not logged in. Your auth token has expired and could not be refreshed, and the environment is non-interactive." The reporter says an interactive terminal goes further and starts a new browser login, which needs the same unreachable server. The reporter's environment was Node.js 22 on macOS and described the platform as irrelevant. [Source](https://github.com/cloudflare/workers-sdk/issues/15886) Real cause in logs: The reporter says debug logging shows the underlying failure as a fetch failure with a timeout, followed by a token refresh failure. In other words, the credentials were never judged by the server. The reporter also says a refresh token may still be valid once the network works again. [Source](https://github.com/cloudflare/workers-sdk/issues/15886) Possible trigger: The reporter describes a network where IPv6 is advertised but not routable and IPv4 latency exceeds Node's default 250 ms happy-eyeballs attempt timeout. On such a network every connection attempt times out. The reporter says that running with Node options disabling network family autoselection and preferring IPv4 made the same refresh succeed, suggesting the credentials were fine. This is one reporter's observation, not documented behavior. [Source](https://github.com/cloudflare/workers-sdk/issues/15886) Hypothesized cause: The reporter says refreshToken() in packages/workers-auth/src/flow.ts catches every error and returns false, so a server rejection and a missing response are indistinguishable. loginOrRefreshIfRequired() then reports a token-expired result and, when interactive, starts a login. No maintainer confirmed this. [Source](https://github.com/cloudflare/workers-sdk/issues/15886) Automated triage evidence: An automated triage comment says it reproduced the non-interactive error with wrangler 4.126.0 and an unreachable endpoint. It reports a connect-timeout cause in the debug log, and says a reachable local mock endpoint refreshed successfully and persisted rotated credentials as a baseline. The comment says it was LLM-generated and may contain errors, so treat it as model-run evidence rather than independent confirmation. [Source](https://github.com/cloudflare/workers-sdk/issues/15886#issuecomment-5842936020) Status: The issue is closed, but the supplied data shows no linked fix commit and no released version, so the fix status is unknown. Closure alone does not establish a fix. If you hit this error, check connectivity to the auth endpoint using wrangler debug logging before concluding that the login is invalid. This is a diagnostic suggestion based on the report, not verified by KFA.