Upgrade heatmaps stile Hotjar: movimenti mouse e anteprima pagina live.

Traccia i movimenti aggregati, overlay a gradienti sull’iframe della pagina e toggle click/move in admin.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/views/admin/analytics/index.html.erb

@@ -40,6 +40,7 @@
           <tr>
             <th><%= t("admin.analytics.index.table.path") %></th>
             <th><%= t("admin.analytics.index.table.pageviews") %></th>
+            <th><%= t("admin.analytics.index.table.moves") %></th>
             <th><%= t("admin.analytics.index.table.clicks") %></th>
             <th><%= t("admin.analytics.index.table.avg_scroll") %></th>
             <th><%= t("admin.analytics.index.table.max_scroll") %></th>
@@ -52,6 +53,7 @@
             <tr>
               <td><code class="admin-mono"><%= row[:page_path] %></code></td>
               <td><%= row[:pageviews] %></td>
+              <td><%= row[:moves] %></td>
               <td><%= row[:clicks] %></td>
               <td class="muted"><%= avg %>%</td>
               <td class="muted"><%= row[:max_scroll] %>%</td>