Implement boxes management module with auto-numbered box creation

- Add boxes_crates database table with BIGINT IDs and 8-digit auto-numbered box_numbers
- Implement boxes CRUD operations (add, edit, update, delete, delete_multiple)
- Create boxes route handlers with POST actions for all operations
- Add boxes.html template with 3-panel layout matching warehouse locations module
- Implement barcode generation and printing with JsBarcode and QZ Tray integration
- Add browser print fallback for when QZ Tray is not available
- Simplify create box form to single button with auto-generation
- Fix JavaScript null reference errors with proper element validation
- Convert tuple data to dictionaries for Jinja2 template compatibility
- Register boxes blueprint in Flask app initialization

app/templates/base.html

@@ -39,6 +39,11 @@
                             <i class="fas fa-check-circle"></i> Quality
                         </a>
                     </li>
+                    <li class="nav-item">
+                        <a class="nav-link" href="{{ url_for('warehouse.warehouse_index') }}">
+                            <i class="fas fa-warehouse"></i> Warehouse
+                        </a>
+                    </li>
                     <li class="nav-item">
                         <a class="nav-link" href="{{ url_for('settings.settings_index') }}">
                             <i class="fas fa-cog"></i> Settings