Fix dropdown menu styling: no rounded corners, no gaps, consistent hover

- border-radius: 0 on all dropdown-menu and dropdown-item
- padding: 0 and margin: 0 on dropdown-menu
- margin-left: 0 on submenu (no gap between parent and child)
- margin-top: -1px on submenu (seamless border overlap)
- CSS hover opens submenu on desktop, click on mobile
- white-space: nowrap on dropdown items
- Fix statistics getFullStats -> getStats
- Fix Twig ?? operator -> default filter on dashboard/statistics
- Asset server (public/asset.php) for production static file serving
- .htaccess rewrite rules for themes/admin/plugins assets

themes/default/assets/js/app.js

@@ -93,34 +93,41 @@ document.addEventListener('DOMContentLoaded', function() {
         });
     });
 
-    // Handle nested dropdowns for touch devices using event delegation
+    // Handle nested dropdowns — toggle submenu on click (for mobile/touch)
+    // On desktop, CSS hover handles submenu display
     document.addEventListener('click', function(e) {
-        const toggle = e.target.closest('.dropdown-submenu .dropdown-toggle');
+        const toggle = e.target.closest('.dropdown-submenu > .dropdown-toggle');
 
         if (toggle) {
             e.preventDefault();
             e.stopPropagation();
 
-            const submenu = toggle.closest('.dropdown-submenu');
+            const submenu = toggle.parentElement;
             const dropdown = submenu.querySelector('.dropdown-menu');
 
-            // Close other submenus at the same level
+            // Close other open submenus at the same level
             const parent = submenu.parentElement;
-            parent.querySelectorAll('.dropdown-submenu').forEach(function(sibling) {
+            parent.querySelectorAll(':scope > .dropdown-submenu').forEach(function(sibling) {
                 if (sibling !== submenu) {
+                    sibling.classList.remove('show');
                     var siblingMenu = sibling.querySelector('.dropdown-menu');
                     if (siblingMenu) siblingMenu.classList.remove('show');
                 }
             });
 
             // Toggle current submenu
-            if (dropdown) dropdown.classList.toggle('show');
+            if (dropdown) {
+                dropdown.classList.toggle('show');
+                submenu.classList.toggle('show');
+            }
             return;
         }
 
         // Close all open submenus when clicking outside
-        document.querySelectorAll('.dropdown-submenu .dropdown-menu.show').forEach(function(menu) {
-            menu.classList.remove('show');
+        document.querySelectorAll('.dropdown-submenu.show').forEach(function(sm) {
+            sm.classList.remove('show');
+            var menu = sm.querySelector('.dropdown-menu');
+            if (menu) menu.classList.remove('show');
         });
     });
 });