Build hn-reader: keyboard-driven Hacker News reader

Vite/React + shadcn/ui frontend with Superhuman-style keyboard nav
(j/k/o/v/e/s/u, feed switching, localStorage caching for instant
loads) backed by an Express API that polls the HN Firebase API into
Postgres and serves cached feeds/comments. Instrumented with
OpenTelemetry (traces/metrics/logs via OTLP/HTTP).

src/components/ui/skeleton.tsx

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