chore(ui): shadcn bileşenleri, use-mobile ve ESLint ayarı

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/components/ui/skeleton.tsx

@@ -0,0 +1,13 @@
+import { cn } from "cn";
+
+function Skeleton({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="skeleton"
+      className={cn("animate-pulse rounded-md bg-muted", className)}
+      {...props}
+    />
+  );
+}
+
+export { Skeleton };