The 'Loader' button appears in the queue panel footer alongside
the existing + Jira, Delete, and Clear Completed buttons. It's
visible whenever CARD/GRANITE/DECOM items exist in the queue.
Clicking it opens the LoaderModal pre-populated with those items'
IPs and hostnames. If specific items are selected, only those are
passed; otherwise all CARD/GRANITE/DECOM items are included.