Fix admin panel close button not working

- Fixed selector to use correct ID 'adminCloseBtn'
- Close button now properly dismisses overlay and returns to edit mode

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

index.html

@@ -5904,7 +5904,7 @@
         document.getElementById('adminTab').addEventListener('click', () => switchTab('admin'));
 
         // Admin overlay close button
-        const adminCloseBtn = document.querySelector('.admin-panel-overlay .close-btn');
+        const adminCloseBtn = document.getElementById('adminCloseBtn');
         if (adminCloseBtn) {
             adminCloseBtn.addEventListener('click', () => {
                 const adminOverlay = document.querySelector('.admin-panel-overlay');