Migliora sessioni admin e rende robusto il logout web.

Aggiunge filtri/colonne (società, orari) e dettaglio leggibile; evita 422 CSRF su logout e non cancella le cover slate custom in sync prod.

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

backend/app/views/layouts/admin.html.erb

@@ -4,7 +4,8 @@
   <title><%= t("admin.layout.title") %></title>
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <meta name="robots" content="noindex, nofollow">
-  <link rel="stylesheet" href="/admin.css?v=11">
+  <%= csrf_meta_tags %>
+  <link rel="stylesheet" href="/admin.css?v=12">
   <% if content_for?(:replay_archive_styles) %>
     <link rel="stylesheet" href="/marketing.css?v=42">
   <% end %>