Bulk preview & publish

We will need polished UX, but I think @mhaack has already built most of this.

Offline discussion: use a modal / dialog instead of a toast so we can provide the list of URLs for either opening or copying.

Start by locating the existing bulk preview and publish work that the issue attributes to @mhaack; no file or test is named. Review the offline discussion before deciding the scope. Done means a polished modal or dialog lists the relevant URLs and supports opening or copying them.

Written by the indexing model from the issue text.