Add Google Analytics 4 (G-PB7M6KHZ9Z)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ChengaDev

public/index.html

@@ -28,6 +28,15 @@
 		<meta property="twitter:image" content="%PUBLIC_URL%/og-image.png" />
 		<meta property="twitter:image:alt" content="ShotClock Pro — free online basketball shot clock" />
 
+		<!-- Google tag (gtag.js) -->
+		<script async src="https://www.googletagmanager.com/gtag/js?id=G-PB7M6KHZ9Z"></script>
+		<script>
+			window.dataLayer = window.dataLayer || [];
+			function gtag(){dataLayer.push(arguments);}
+			gtag('js', new Date());
+			gtag('config', 'G-PB7M6KHZ9Z');
+		</script>
+
 		<script
 			data-ad-client="ca-pub-1951283706310480"
 			async