Apple-style audiobook card & modal redesign

Add Apple-style UI refinements and UX improvements across audiobooks.

- Add app icons and update manifest/layout to reference new 180x180 and 1024x1024 app icons.
- Add global CSS animations (shimmer and toast slide-in) for improved skeletons/toasts.
- Refactor AudiobookCard: new "cover-first" design, accessibility improvements, hover actions, request handling, inline toast/error UI, status helper (status -> badge/state mapping), simplified metadata layout, and polished animations/visuals. Removed some legacy imports and adjusted request UX (shorter toasts, error timing).
- Enhance AudiobookDetailsModal: mobile-first sticky header, desktop modal polish, improved status logic, toast/notification helper, ASIN copy behavior, ebook request flows, uses preferences (squareCovers) and various layout/formatting tweaks.
- Propagate hideRequestActions from bookdate page (bookdate/page.tsx).

These changes focus on visual polish, accessibility, and smoother request/notification UX. Files changed: public manifest & icons, globals.css, app/layout.tsx, bookdate page, AudiobookCard, AudiobookDetailsModal, and PreferencesContext (context usage updated).

src/app/globals.css

@@ -170,3 +170,29 @@ body {
   -webkit-backface-visibility: hidden;
   transform-origin: center center;
 }
+
+/* Premium Shimmer Animation for Skeletons */
+@keyframes shimmer {
+  0% {
+    transform: translateX(-100%);
+  }
+  100% {
+    transform: translateX(100%);
+  }
+}
+
+/* Smooth Toast Slide In */
+@keyframes toast-slide-in {
+  0% {
+    opacity: 0;
+    transform: translate(-50%, 20px);
+  }
+  100% {
+    opacity: 1;
+    transform: translate(-50%, 0);
+  }
+}
+
+.animate-toast-in {
+  animation: toast-slide-in 0.3s ease-out;
+}