B2B-88: add starter kit structure and elements

packages/ui/src/makerkit/loading-overlay.tsx

@@ -0,0 +1,33 @@
+import type { PropsWithChildren } from 'react';
+
+import { cn } from '../lib/utils';
+import { Spinner } from './spinner';
+
+export function LoadingOverlay({
+  children,
+  className,
+  fullPage = true,
+  spinnerClassName,
+}: PropsWithChildren<{
+  className?: string;
+  spinnerClassName?: string;
+  fullPage?: boolean;
+  displayLogo?: boolean;
+}>) {
+  return (
+    <div
+      className={cn(
+        'flex flex-col items-center justify-center space-y-4',
+        className,
+        {
+          [`bg-background fixed top-0 left-0 z-100 h-screen w-screen`]:
+            fullPage,
+        },
+      )}
+    >
+      <Spinner className={spinnerClassName} />
+
+      <div className={'text-muted-foreground text-sm'}>{children}</div>
+    </div>
+  );
+}