This internal helper performs an HTTP GET request to the given URL
(typically generated by ids_url_build()) and parses the RSS XML
response into a structured data.frame.
ids_download(url, timeout = 60)A data.frame with columns:
Numeric identifier extracted from the GUID.
Record title as published in the service.
Full GUID (unique resource identifier).
Returns an empty data.frame if the request fails or no items are found.
Character. The complete request URL.
Numeric. Request timeout in seconds (default = 60).