Function is_transient_error

core/src/retry.rs:191–217

Heuristic: is this a transient *network* error worth retrying — a timeout, connection reset/refused/closed, broken pipe, DNS failure, or a request that dropped mid-flight? These carry no HTTP status (so `is_retryable_status` can't see them), yet Claude Code retries them just like 429/5xx. We only have the error's rendered text (a `CodeError`/`anyhow::Error` chain) to classify.

(e: &E)

/// can't see them), yet Claude Code retries them just like 429/5xx. We only have
/// the error's rendered text (a `CodeError`/`anyhow::Error` chain) to classify.
pub fn is_transient_error<E: std::fmt::Display>(e: &E) -> bool {
    let m = e.to_string().to_lowercase();
    [
        "timed out",
        "timeout",
        "connection reset",
        "connection refused",
        "connection closed",
        "connection aborted",
        "connection error",
        "broken pipe",
        "reset by peer",
        "error sending request",
        "incomplete message",
        "unexpected eof",
        "dns error",
        "unreachable",
        "tls handshake",
        "request error",
        "body error",
        "decoding response",
        "channel closed",
        "stream closed",
    ]
    .iter()
    .any(|p| m.contains(p))
}

#[cfg(test)]
mod tests {