Fix: Add safe localStorage wrapper and QZ Tray toggle feature

- Created storage-utils.js with safeStorage wrapper to prevent tracking prevention errors
- Updated script.js to use safeStorage for theme persistence
- Added conditional QZ Tray connection based on 'Enable Scan to Boxes' toggle
- Fixed 404 error by removing non-existent /api/backup/path endpoint call
- Enhanced fg_scan.html to disable QZ Tray and socket connections when toggle is off
- Prevents console errors when browser tracking prevention blocks localStorage access

py_app/app/templates/base.html

@@ -65,6 +65,8 @@
     <div class="main-content">
         {% block content %}{% endblock %}
     </div>
+    <!-- Safe localStorage utility (must load first) -->
+    <script src="{{ url_for('static', filename='js/storage-utils.js') }}"></script>
     {% if request.endpoint != 'main.fg_quality' %}
     <script src="{{ url_for('static', filename='script.js') }}"></script>
     {% endif %}