Aggiunge overlay server-side burn-in e stabilizza diretta live.

Tabellone, badge e brand sono ricodificati nel flusso _air via OverlayRelay;
sync punteggio HTTP, volume condiviso rails/sidekiq, qualità 720p migliorata
e badge CONNECTING in ripresa da pausa.

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

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

@@ -7,7 +7,7 @@
     <%= render "shared/meta_tags" %>
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.2/css/all.min.css" integrity="sha512-SnH5WK+bZxgPHs44uWIX+LLJAJ9/2PkPKZ5QiAj6Ta86w+fsb2TkcmfRyVX3pBnMFcV7oQPJkl9QevSCWr3W6A==" crossorigin="anonymous" referrerpolicy="no-referrer">
     <link rel="stylesheet" href="/marketing.css?v=36">
-    <link rel="stylesheet" href="/live.css?v=4">
+    <link rel="stylesheet" href="/live.css?v=22">
     <%= yield :head %>
   </head>
   <body<% if MatchLiveTv.google_analytics_configured? %> data-ga-id="<%= MatchLiveTv.google_analytics_measurement_id %>"<% end %>>