chore(frontend): untrack node_modules and build artifacts; update .gitignore

Author: austinLorenzMccoy

.gitignore

@@ -62,4 +62,11 @@ coverage.xml
 # Logs
 *.log
 
-Network_Security.egg-info/
+Network_Security.egg-info/
+
+# Node / Next.js (frontend)
+frontend/node_modules/
+frontend/.next/
+frontend/out/
+frontend/.turbo/
+frontend/.vercel/