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.

CLAUDE.md

@@ -65,7 +65,9 @@ Entry point is `src/js/starter.js`, loaded from `src/index.html`. Flow on load (
    `flipView` (180° GSAP-animated turn between front/back view), `addMarker` (in-scene hotspot with a video
    popup).
 6. **Pricing is server-side only**: `backoffice/app/Support/Configuratore/CalcolatorePrezzo.php`.
-   `prezzo = base × (1 + supplementi % / 100) + supplementi fissi + variazione vetro` (VAT excluded). Base is
+   Computed in cascading phases, each phase's percentages applied to the previous phase's total (VAT
+   excluded): `serramento = base × (1 + finitura %)`, then profili extra on the serramento (measures +
+   finishes only), then the other options (telaio, apertura, accessori), then `+ variazione vetro`. Base is
    the first grid size ≥ the requested one (mm). Supplements come from `opzioni` rows (finish type
    bianco/uniforme/bicolore, hinges, profili extra, ...): percentage, fixed, or per linear metre
    (ml from L/H multipliers + extra mm). Groups with `ui = multipla` (profili extra) accept several codes,