feat: add blocks showcase and restructure app

src/components/main-nav.tsx

@@ -0,0 +1,36 @@
+"use client";
+
+import Link from "next/link";
+
+import { siteNavigation } from "@/lib/site-navigation";
+import { Button } from "@/components/ui/button";
+import { cn } from "@/lib/utils";
+
+export function MainNav({ className, ...props }: React.ComponentProps<"nav">) {
+  const navItems = siteNavigation
+    .find((group) => group.title === "Pages")
+    ?.items.filter((item) => item.title !== "Home");
+
+  if (!navItems) return null;
+
+  return (
+    <nav className={cn("items-center gap-1", className)} {...props}>
+      {navItems.map((item) => (
+        <Button
+          key={item.href}
+          variant="ghost"
+          asChild
+          size="sm"
+          className="px-2.5"
+        >
+          <Link
+            href={item.href}
+            className="relative inline-flex items-center gap-1.5"
+          >
+            <span>{item.title}</span>
+          </Link>
+        </Button>
+      ))}
+    </nav>
+  );
+}