Major updates: Setup environment, database, permissions and admin access

- Created virtual environment and installed requirements
- Set up MariaDB database with user 'sa' and database 'recticel'
- Created order_for_labels table for printing functionality
- Implemented role-based permissions system with admin role
- Added admin access to print label modules and etichete functionality
- Fixed template routing issues in main_page_etichete.html
- Updated app to run on port 8781 with network access (0.0.0.0)
- Added systemd service file for background deployment
- Created installation documentation

py_app/instance/external_server.conf

@@ -1,5 +1,5 @@
 server_domain=localhost
 port=3602
-database_name=trasabilitate_database
-username=trasabilitate
-password=Initial01!
+database_name=recticel
+username=sa
+password=12345678