ver. 0.286: Layouts, Menu, Pages frontend migration to Domain

- Add 6 frontend methods to LayoutsRepository (Redis cache, 3-level fallback)
- Add 6 frontend methods to PagesRepository (Redis cache, recursive pages)
- Create front\Views\Menu (clean VIEW replacing front\view\Menu)
- Delete front\factory\Layouts, Menu, Pages + front\view\Menu + dead submenu.php
- Fix null $lang_id TypeError in check_url_params() (remove string type hint + ?? '')
- Optimize Helpers::htacces() from 3 layout calls to 1
- Tests: 470 OK, 1484 assertions (+16 new)

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

templates/site/languages.php

@@ -7,7 +7,7 @@
           <ul>
             <? foreach ( $this -> languages as $lg ):?>
               <li <? if ( $lang_id == $lg['id'] ) echo 'class="active"';?>>
-                <a href="<?= \front\factory\Pages::lang_url( $page['id'], $lg['id'] );?>" title="Język: <?= $lg['name'];?>">
+                <a href="<?= ( new \Domain\Pages\PagesRepository( $GLOBALS['mdb'] ) )->frontLangUrl( $page['id'], $lg['id'] );?>" title="Język: <?= $lg['name'];?>">
                   <img src="/admin/css/lang-<?= $lg['id'];?>.jpg" alt="Język: <?= $lg['name'];?>">
                 </a>
               </li>