feat: add loading and page skeleton components

app/loading.tsx

@@ -0,0 +1,5 @@
+import { PageSkeleton } from "@/components/page-skeleton";
+
+export default function Loading() {
+  return <PageSkeleton />;
+}

components/page-skeleton.tsx

@@ -0,0 +1,26 @@
+import { Skeleton } from "poyraz-ui/atoms";
+
+export function PageSkeleton() {
+  return (
+    <section aria-busy="true" aria-live="polite" className="space-y-8">
+      <div className="space-y-3">
+        <Skeleton className="h-5 w-28 rounded-sm" />
+        <Skeleton className="h-10 w-full rounded-sm" />
+        <Skeleton className="h-4 w-5/6 rounded-sm" />
+        <Skeleton className="h-4 w-2/3 rounded-sm" />
+      </div>
+
+      <div className="grid gap-4 sm:grid-cols-2">
+        <Skeleton className="h-40 w-full rounded-sm" />
+        <Skeleton className="h-40 w-full rounded-sm" />
+      </div>
+
+      <div className="space-y-3">
+        <Skeleton className="h-4 w-24 rounded-sm" />
+        <Skeleton className="h-4 w-full rounded-sm" />
+        <Skeleton className="h-4 w-full rounded-sm" />
+        <Skeleton className="h-4 w-4/5 rounded-sm" />
+      </div>
+    </section>
+  );
+}