User management and module improvements

- Added daily_mirror module to permissions system
- Fixed user module management - updates now work correctly
- Implemented dashboard module filtering based on user permissions
- Fixed warehouse create_locations page (config parser and delete)
- Implemented POST-Redirect-GET pattern to prevent duplicate entries
- Added application license system with validation middleware
- Cleaned up debug logging code
- Improved user module selection with fetch API instead of form submit

py_app/app/templates/settings.html

@@ -51,6 +51,22 @@
         </small>
     </div>
 
+    {% if session.role == 'superadmin' %}
+    <div class="card" style="margin-top: 32px;">
+        <h3>🖨️ Print Extension Management</h3>
+        <p><strong>QZ Tray Pairing Keys:</strong> Manage printer connection keys</p>
+        <p>Control access to direct printing functionality for label modules</p>
+        <div style="margin-top: 15px;">
+            <a href="{{ url_for('main.download_extension') }}" class="btn" style="background-color: #4caf50; color: white;">
+                🔑 Manage Pairing Keys
+            </a>
+        </div>
+        <small style="display: block; margin-top: 10px; color: #666;">
+            Generate and manage pairing keys for QZ Tray printer integration
+        </small>
+    </div>
+    {% endif %}
+
     {% if session.role in ['superadmin', 'admin'] %}
     <div class="card backup-card" style="margin-top: 32px;">
         <h3>💾 Database Backup Management</h3>