/cdn-cgi/rum endpoint now returns 405 for non-POST requests

The /cdn-cgi/rum beacon endpoint now returns 405 Method Not Allowed for non-POST requests instead of 404 Not Found. The response includes an Allow: POST, OPTIONS header per RFC 9110 §15.5.6.

Previously, sending a GET or other non-POST request to this endpoint returned a 404, which was misleading because it suggested the endpoint did not exist. The new 405 response clearly indicates that the endpoint exists but only accepts POST requests.

The Web Analytics beacon (beacon.min.js) already uses POST for all metric submissions, so this change does not affect normal beacon operation. OPTIONS requests for CORS preflight continue to work as before.

For more information, refer to the Web Analytics FAQ.