feat: integrate Tailwind CSS with custom theme and animations

Added Tailwind CSS and tw-animate-css imports to globals.css. Introduced a custom dark variant and an extensive @theme inline block with CSS variables for colors, radii, and animations. Included keyframes for shimmer-slide, spin-around, gradient, shine, and background-position-spin to enable consistent theming and dynamic UI effects across the application.

components/ui/skeleton.tsx

@@ -0,0 +1,16 @@
+import { cn } from "@/lib/utils";
+
+function Skeleton({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) {
+  return (
+    <div
+      className={cn("animate-pulse rounded-md bg-muted", className)}
+      {...props}
+    />
+  );
+}
+
+export { Skeleton };
+