Move dns.setDefaultResultOrder to server.js top-level

The DNS ipv4first setting must be applied before any module loads
the https/http modules. When set inside cardApi.js helper, it's
too late — the https module has already cached DNS resolution
behavior. Moving it to the very top of server.js ensures it
takes effect globally for all outbound connections.

backend/server.js

@@ -1,6 +1,10 @@
 // CVE Management Backend API
 // Install: npm install express pg multer cors dotenv bcryptjs cookie-parser
 
+// Force IPv4-first DNS resolution globally — must be set before any network modules load.
+// card.charter.com has IPv6 AAAA records that are unreachable from this network.
+require('dns').setDefaultResultOrder('ipv4first');
+
 require('dotenv').config();
 
 const express = require('express');