Reduce status polling load and add 1Hz ready LED blink

templates/index.html

@@ -146,7 +146,7 @@
     document.getElementById('shutdownBtn').addEventListener('click', () => triggerSystemAction('shutdown'));
 
     refreshStatus();
-    setInterval(refreshStatus, 5000);
+    setInterval(refreshStatus, 15000);
   </script>
 </body>
 </html>