Force IPv4 for CARD API requests

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.

backend/helpers/cardApi.js

@@ -57,6 +57,7 @@ function acquireToken(timeout) {
             port:     fullUrl.port || (isHttps ? 443 : 80),
             path:     fullUrl.pathname + fullUrl.search,
             method:   'POST',
+            family:   4, // Force IPv4 — IPv6 is unreachable from this network
             headers:  {
                 'accept':        'application/json',
                 'authorization': 'Basic ' + authString,
@@ -150,6 +151,7 @@ async function cardRequest(method, urlPath, body, options) {
                 port:     fullUrl.port || (isHttps ? 443 : 80),
                 path:     fullUrl.pathname + fullUrl.search,
                 method,
+                family:   4, // Force IPv4 — IPv6 is unreachable from this network
                 headers,
                 timeout,
             };