Allinea i KPI su due righe e aggiunge lo storico orario degli invii confermati.

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

app/views/mailings/dashboard.html.erb

@@ -26,7 +26,7 @@
     </div>
   <% end %>
 
-  <div class="grid grid-cols-2 gap-3 md:grid-cols-3 xl:grid-cols-5">
+  <div class="grid grid-cols-2 gap-3 md:grid-cols-3">
     <div class="<%= card_class %> p-4">
       <div class="text-xs uppercase tracking-wide text-zinc-500">In corso</div>
       <div class="mt-1 text-2xl font-semibold tabular-nums"><%= @active_mailings.size %></div>
@@ -41,6 +41,18 @@
         <% end %>
       </div>
     </div>
+    <div class="<%= card_class %> p-4">
+      <div class="text-xs uppercase tracking-wide text-zinc-500">Storico invio</div>
+      <div class="mt-2 flex items-end gap-0.5" style="height: 2.5rem" role="img" aria-label="Invii confermati nelle ultime 12 ore">
+        <% @hourly_throughput.hourly_history.each do |bucket| %>
+          <% pct = (bucket[:count].to_f / @hourly_throughput.history_max * 100).round %>
+          <div class="flex-1 rounded <%= bucket[:count].positive? ? "bg-emerald-500" : "bg-zinc-200 dark:bg-zinc-700" %>"
+               style="height: <%= bucket[:count].positive? ? [pct, 12].max : 8 %>%"
+               title="<%= bucket[:at].strftime("%H:%M") %>: <%= bucket[:count] %>"></div>
+        <% end %>
+      </div>
+      <div class="mt-1 text-xs text-zinc-500"><%= @hourly_throughput.history_total %> inviate · ultime 12 ore</div>
+    </div>
     <div class="<%= card_class %> p-4">
       <div class="text-xs uppercase tracking-wide text-zinc-500">In pausa (fascia)</div>
       <div class="mt-1 text-2xl font-semibold tabular-nums"><%= @paused_mailings.size %></div>