feat(52-mobile-main-menu): hamburger + slide-in overlay sidebar na mobile

Zastapienie niedzialajacej nawigacji horyzontalnej pelnoekranowym
overlay sidebar z hamburgerem, backdrop i animacja CSS transform.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

resources/views/layouts/app.php

@@ -115,8 +115,17 @@
       </nav>
     </aside>
 
+    <div class="sidebar-backdrop" id="js-sidebar-backdrop"></div>
+
     <div class="app-main">
       <header class="topbar">
+        <button class="topbar__hamburger" id="js-hamburger" type="button" aria-label="Otwórz menu">
+          <svg width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <line x1="3" y1="6" x2="21" y2="6"/>
+            <line x1="3" y1="12" x2="21" y2="12"/>
+            <line x1="3" y1="18" x2="21" y2="18"/>
+          </svg>
+        </button>
         <div>
           <strong><?= $e((string) (($user['name'] ?? '') !== '' ? $user['name'] : ($user['email'] ?? ''))) ?></strong>
         </div>
@@ -167,6 +176,60 @@
         }
       });
     });
+
+    // Mobile menu
+    var hamburger = document.getElementById('js-hamburger');
+    var backdrop = document.getElementById('js-sidebar-backdrop');
+    var mobileQuery = window.matchMedia('(max-width: 768px)');
+
+    function closeMobileMenu() {
+      sidebar.classList.remove('is-mobile-open');
+      backdrop.classList.remove('is-visible');
+      document.body.classList.remove('no-scroll');
+    }
+
+    function openMobileMenu() {
+      sidebar.classList.add('is-mobile-open');
+      backdrop.classList.add('is-visible');
+      document.body.classList.add('no-scroll');
+    }
+
+    if (hamburger) {
+      hamburger.addEventListener('click', function () {
+        if (sidebar.classList.contains('is-mobile-open')) {
+          closeMobileMenu();
+        } else {
+          openMobileMenu();
+        }
+      });
+    }
+
+    if (backdrop) {
+      backdrop.addEventListener('click', closeMobileMenu);
+    }
+
+    // Close button (collapse-btn acts as X on mobile)
+    collapseBtn.addEventListener('click', function () {
+      if (mobileQuery.matches) {
+        closeMobileMenu();
+      }
+    });
+
+    // Close on navigation link click (mobile only)
+    sidebar.querySelectorAll('.sidebar__link, .sidebar__sublink').forEach(function (link) {
+      link.addEventListener('click', function () {
+        if (mobileQuery.matches) {
+          closeMobileMenu();
+        }
+      });
+    });
+
+    // Reset state on resize to desktop
+    mobileQuery.addEventListener('change', function (e) {
+      if (!e.matches) {
+        closeMobileMenu();
+      }
+    });
   })();
   </script>
 </body>