feat: enhance formatUptime to include minutes

- Now formats as "Xd Yh Zm", "Yh Zm", or "Zm" depending on value size
- Backlog: mark Uptime Duration as done

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/components/NodeCard.js

@@ -26,7 +26,10 @@ function formatUptime(seconds) {
   if (!seconds) return 'N/A';
   const days = Math.floor(seconds / 86400);
   const hours = Math.floor((seconds % 86400) / 3600);
-  return `${days}d ${hours}h`;
+  const minutes = Math.floor((seconds % 3600) / 60);
+  if (days) return `${days}d ${hours}h ${minutes}m`;
+  if (hours) return `${hours}h ${minutes}m`;
+  return `${minutes}m`;
 }
 
 /**