card.charter.com resolves to both IPv4 (47.43.51.7) and IPv6
(2600:6c7f:9340:ca5::7). IPv6 is unreachable from this network,
causing Node.js to attempt IPv6 first, wait for timeout, then
fall back — but the 15s request timeout fires before the fallback
completes. Adding family: 4 to both acquireToken and doRequest
forces IPv4 resolution, matching curl behavior.