Aggiunge sulla dashboard invii il KPI mail/ora dagli invii SMTP confermati.

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

test/controllers/mailings_controller_test.rb

@@ -16,6 +16,26 @@ class MailingsControllerTest < ActionDispatch::IntegrationTest
     assert_match(/Invii email/, response.body)
   end
 
+  test "dashboard shows hourly send throughput" do
+    login_as users(:admin)
+    follow_redirect! if response.redirect?
+
+    mailing = create_mailing(identity: @identity, audience: "to_send")
+    org = organizations(:acme)
+    mailing.mailing_recipients.create!(
+      organization: org,
+      contact: org.contacts.first,
+      email: org.email,
+      status: "sent",
+      sent_at: 8.minutes.ago
+    )
+
+    get dashboard_mailings_path(project_code: @project.code)
+    assert_response :success
+    assert_select "div", text: "Mail / ora"
+    assert_match(/1 ultimi 15 min/, response.body)
+  end
+
   test "creates a draft and opens audience filters" do
     login_as users(:admin)
     follow_redirect! if response.redirect?