feat: implement skeleton loading across all dynamic sections

Added a shimmering Skeleton component. Integrated loading states for Hero, About (Bento Grid), Reading Log, Projects Archive, and Library pages for a premium UX.

app/components/CurrentlyReading.tsx

@@ -5,6 +5,7 @@ import { BookOpen } from "lucide-react";
 import { useEffect, useState } from "react";
 import { useTranslations } from "next-intl";
 import Image from "next/image";
+import { Skeleton } from "./ui/Skeleton";
 
 interface CurrentlyReading {
   title: string;
@@ -54,8 +55,26 @@ const CurrentlyReading = () => {
     fetchCurrentlyReading();
   }, []); // Leeres Array = nur einmal beim Mount
 
+  if (loading) {
+    return (
+      <div className="space-y-4">
+        <div className="flex flex-col sm:flex-row gap-4 items-start">
+          <Skeleton className="w-24 h-36 sm:w-28 sm:h-40 rounded-lg shrink-0" />
+          <div className="flex-1 space-y-3 w-full">
+            <Skeleton className="h-6 w-3/4" />
+            <Skeleton className="h-4 w-1/2" />
+            <div className="space-y-2 pt-4">
+              <Skeleton className="h-2 w-full" />
+              <Skeleton className="h-2 w-full" />
+            </div>
+          </div>
+        </div>
+      </div>
+    );
+  }
+
   // Zeige nichts wenn kein Buch gelesen wird oder noch geladen wird
-  if (loading || books.length === 0) {
+  if (books.length === 0) {
     return null;
   }