feat(nav): close P0/P1 parity gaps (nav style, history, plate, admin build)

Wire header_nav_style transparent/blur, login history sync, plate publish
type, clean dead search CSS, rebuild admin SPA locally (build gitignored).

assets/css/frontend/nav/zib-search-box.css

@@ -92,9 +92,8 @@
   display: none;
 }
 
-/* Full navbar-search slide (layout 1/3) */
+/* Full navbar-search slide (layout 1/3) — position/transition from zib-navbar-core */
 .navbar-search {
-  position: fixed;
   left: 0;
   right: 0;
   top: 0;