Aggiunge il rilevamento di invio e apertura delle email di campagna.

Ogni destinatario mostra se la mail è partita e se è stata aperta, con conteggi in dashboard.

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

app/views/mailings/dashboard.html.erb

@@ -73,7 +73,7 @@
             </div>
             <div class="mt-3"><%= progress_bar(mailing.progress_percentage) %></div>
             <div class="mt-2 text-xs text-zinc-500">
-              <%= mailing.sent_count %> inviate · <%= mailing.pending_count %> in coda
+              <%= mailing.sent_count %> inviate · <%= mailing.opened_count %> aperte · <%= mailing.pending_count %> in coda
               <% if mailing.sending? && mailing.next_send_at.present? && mailing.next_send_at > Time.current %>
                 · Riparte <%= l(mailing.next_send_at, format: :short) %>
               <% end %>
@@ -106,6 +106,7 @@
                 <%= progress_bar(mailing.progress_percentage) %>
                 <div class="mt-1 text-xs text-zinc-500">
                   <%= mailing.sent_count %> inviate
+                  · <%= mailing.opened_count %> aperte
                   · <%= mailing.pending_count %> in coda
                   <% if mailing.failed_count.positive? %>
                     · <span class="text-rose-700"><%= mailing.failed_count %> errori</span>