fix: replace vulnerable ip package with ipaddr.js + node built-ins

ip had a high severity SSRF vuln (GHSA-2p57-rm9w-gvfp) with no upstream fix.
Replace with:
- net.isIPv4/isIPv6 (Node built-in) for format validation
- ipaddr.js for CIDR subnet matching

Add package-lock.json for reproducible builds (required for npm ci).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dashboard/package.json

@@ -12,7 +12,7 @@
   "dependencies": {
     "dotenv": "*",
     "express": "*",
-    "ip": "*",
+    "ipaddr.js": "*",
     "node-fetch": "^2"
   }
 }