feat: implement discount and transport features in the quote system

- Added maximum discount settings configurable by the administrator.
- Implemented discount calculations in the quote confirmation process.
- Introduced transport options with associated costs, including handling for exceeding maximum piece limits.
- Updated frontend to display discounts and transport information in the quote summary.
- Created new database migrations for storing discount and transport settings.
- Developed a new Filament page for managing global discount settings.
- Enhanced email templates to include discount and transport details.
- Added tests to ensure proper functionality of discounts and transport calculations.

backoffice/app/Http/Controllers/Api/AuthController.php

@@ -67,6 +67,8 @@ class AuthController extends Controller
                 'provincia' => $cliente->provincia,
                 'note' => $cliente->note,
             ],
+            // Sconti massimi (%) applicabili al preventivo prima dell'invio (0 = non consentito).
+            'sconti' => $cliente->scontiMassimi(),
         ]);
     }
 }