fix: comprehensive UI/UX accessibility and usability improvements

Public site: skip-to-content link, mobile menu focus trap + Escape key,
aria-current on nav, keyboard navigation for carousels/tabs/articles,
ARIA roles (tablist/tab/tabpanel, combobox/listbox, region, dialog),
form labels + aria-describedby, 44px touch targets, semantic HTML
(<time>, <del>), prefers-reduced-motion on Hero scroll hijack,
mobile schedule filters, URL hash sync on scroll for correct refresh.

Admin panel: password toggle aria-label, toast aria-live regions,
SelectField keyboard navigation (Arrow/Enter/Escape), aria-invalid
on validation errors, sidebar hamburger aria-label/expanded,
nav aria-label, ArrayEditor aria-expanded on collapsible items.

src/app/styles/components.css

@@ -6,6 +6,7 @@
   @apply hover:bg-gold-light hover:shadow-[0_0_30px_rgba(201,169,110,0.35)];
   @apply dark:bg-gold dark:text-black;
   @apply dark:hover:bg-gold-light dark:hover:shadow-[0_0_30px_rgba(201,169,110,0.35)];
+  @apply focus:outline-none focus-visible:ring-2 focus-visible:ring-gold-light focus-visible:ring-offset-2 focus-visible:ring-offset-black;
 }
 
 /* ===== Scrollbar ===== */