Site polish: tighter modalidades spacing, less schedule redundancy, plan section styling

- Modalidades: reduce gap between cards
- Horário: drop the day-title above the grid in single-day mode (the active
  day-filter button already names it); restyle "Guardar horário" as a plain
  link and drop the "(JPG)" suffix
- Mensalidades: give "Escolhe o teu plano" the same dark hammered-metal
  background as the reviews/footer sections instead of the plain light one

site/includes/horario.php

@@ -37,7 +37,7 @@ foreach ($rows as $d) { $grid[$d['dia_semana']][$d['hora_inicio']][] = $d; }
         </div>
         <div class="text-center mb-2">
           <button type="button" class="schedule-dl-btn" id="scheduleDownloadCf">
-            <i class="fas fa-download" aria-hidden="true"></i> Guardar horário (JPG)
+            <i class="fas fa-download" aria-hidden="true"></i> Guardar horário
           </button>
         </div>
       </div>