fix: address bar not updating on post click (htmx history off + hx-push-url no-op)
Links with their own hx-get + hx-push-url (post-card/post-tile/topnav) do not go
through the plain-link-boost and hx-push-url does nothing now that
htmx.config.historyEnabled=false. New global htmx:beforeSwap listener does its own
history.pushState based on hx-push-url of the triggering element. Programmatic
htmx.ajax (boost/popstate) has no elt with hx-push-url -> no double push.
Co-Authored-By: Claude <noreply@…>