ver. 0.288: BasketCalculator + ShopBasketController migration, cms\Layout removal

- Migrate front\factory\ShopBasket → Domain\Basket\BasketCalculator (4 static methods, 18 callers updated)
- Migrate front\controls\ShopBasket → front\Controllers\ShopBasketController (camelCase, instance methods)
- Add snake_case→camelCase action dispatch for new controllers in Site::route()
- Update title()/page_title() to check front\Controllers\ before fallback
- Remove cms\Layout class (replaced by $layoutsRepo->find())
- Add 8 tests for BasketCalculator (484 tests, 1528 assertions)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

templates/shop-basket/summary-view.php

@@ -173,7 +173,7 @@
       event: "begin_checkout",
       ecommerce: {
         currency: "PLN",
-        value: <?= \Shared\Helpers\Helpers::normalize_decimal( \front\factory\ShopBasket::summary_price( $this -> basket, $this -> coupon ) );?>,
+        value: <?= \Shared\Helpers\Helpers::normalize_decimal( \Domain\Basket\BasketCalculator::summaryPrice( $this -> basket, $this -> coupon ) );?>,
         items: [
           <?= $begin_checkout_items;?>
         ]