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/Providers/Filament/AdminPanelProvider.php

@@ -6,6 +6,7 @@ use Filament\Http\Middleware\Authenticate;
 use Filament\Http\Middleware\AuthenticateSession;
 use Filament\Http\Middleware\DisableBladeIconComponents;
 use Filament\Http\Middleware\DispatchServingFilamentEvent;
+use Filament\Navigation\NavigationItem;
 use Filament\Pages;
 use Filament\Panel;
 use Filament\PanelProvider;
@@ -39,6 +40,12 @@ class AdminPanelProvider extends PanelProvider
             ->pages([
                 Pages\Dashboard::class,
             ])
+            ->navigationItems([
+                NavigationItem::make('Apri configuratore')
+                    ->url(fn (): string => config('preventivi.configuratore_url'), shouldOpenInNewTab: true)
+                    ->icon('heroicon-o-arrow-top-right-on-square')
+                    ->sort(100),
+            ])
             ->discoverWidgets(in: app_path('Filament/Widgets'), for: 'App\\Filament\\Widgets')
             ->widgets([])
             ->middleware([