Initial commit: Shopify storefront Next.js template

Next.js 16 + React 19 storefront template with Shopify Storefront API
integration, Tailwind v4, and shadcn/ui components.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0111qSr3KopyGRsJ6LznR1xZ

components/ui/spinner.tsx

@@ -0,0 +1,38 @@
+import React from 'react';
+import { cn } from '@/lib/utils';
+
+interface SpinnerProps extends React.ComponentProps<'svg'> {
+  size?: 'sm' | 'md' | 'lg' | 'xl';
+}
+
+const sizeClasses = {
+  sm: 'size-3',
+  md: 'size-4',
+  lg: 'size-6',
+  xl: 'size-8',
+};
+
+function Spinner({ className, size = 'md', ...props }: SpinnerProps) {
+  return (
+    <svg
+      role="status"
+      aria-label="Loading"
+      xmlns="http://www.w3.org/2000/svg"
+      width="24"
+      height="24"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+      strokeLinejoin="round"
+      className={cn('animate-spin', sizeClasses[size], className)}
+      {...props}
+    >
+      <path d="M21 12a9 9 0 1 1-6.219-8.56" />
+    </svg>
+  );
+}
+
+export { Spinner };
+export type { SpinnerProps };