feat(home): replace horizontal carousel with vertical scroll-snap stack

For multi-frame setups, switch from side-swipe carousel + dot indicators
to a vertical scroll-snap stack of full-size cards. Each frame gets its
own page-height slide; flicking up/down moves between frames with the
same snap-stop feel as the horizontal version. Removes ~30 lines of
carousel scroll-tracking JS and the dot navigation.

Single-frame layout unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

public/build/index.html

@@ -14,7 +14,7 @@
     <meta name="mobile-web-app-capable" content="yes" />
     <meta name="apple-mobile-web-app-status-bar-style" content="default" />
     <meta name="apple-mobile-web-app-title" content="pictureFrame" />
-    <script type="module" crossorigin src="/build/assets/index-aP_uBWCi.js"></script>
+    <script type="module" crossorigin src="/build/assets/index-Dt4UyE7n.js"></script>
     <link rel="modulepreload" crossorigin href="/build/assets/_plugin-vue_export-helper-DVo1OUMD.js">
     <link rel="stylesheet" crossorigin href="/build/assets/index-BlLBHR1q.css">
   </head>