refactor: migrate app to Alpine.js

style.css

@@ -34,7 +34,7 @@
     }
 }
 * { box-sizing: border-box; }
-[hidden] { display: none !important; }
+[hidden], [x-cloak] { display: none !important; }
 body { margin: 0; padding: clamp(1rem, 4vw, 3rem); background: var(--background); color: var(--foreground); font-family: plexmono, Consolas, monospace; line-height: 1.6; }
 main { max-width: 1120px; margin: auto; min-width: 0; }
 header { margin-bottom: 2rem; }