Dato Agent: answers with a slug instead of the full website URL #164

Problem

When an editor asks for the link to a page, Dato Agent returns the record slug. It does not include the website domain, so the editor still has to build the URL by hand.

The Web Previews plugin already knows how to turn a record into full preview URLs, but Dato Agent does not use that setup.

Expected

When an editor asks for a page URL, the agent should call the Web Previews preview endpoints and return the full URLs. If an editor cannot read that plugin's settings, an admin should be able to import a copy into Dato Agent. If no preview endpoint is available, the agent should build the URL from a configured website address and the record slug, and say so. If neither is configured, it should return the slug and say the full URL is unavailable.