A lone {contact: Label} line in article Markdown renders a
.contact-trigger button that opens the visitor panel (pagerite.js binds
the click and lazy-loads the contact bundle; inert in the editor
preview, whose resolver now matches the served page). The on-demand
bundle's URLs ride in the pagerite-assets config like langselect's, and
the build gets a contact entry point. Description/card mining renders
resolve the tag to nothing.