- Added invoice generation logic using DomPDF.
- Integrated invoice data retrieval from the API.
- Implemented language determination for invoices based on customer data.
- Added options to email invoices to customers and admin.
- Included HTML output option for direct viewing in the browser.
- Ensured proper redirection and error handling throughout the process.
- Added software.php for managing software versions, including download and purchase actions.
- Created upgrade_paths.php for handling upgrade paths management.
- Developed user_licenses.php for managing user licenses.
- Introduced version_access_rules.php for managing access rules for software versions.
- Implemented frontend functions in functions.js for interacting with the software upgrade API.
- Added version_access.php for user access validation and license management.
- Created upgrades.php for displaying available upgrades and handling user interactions.
- Enhanced UI with responsive design and progress indicators for downloads and purchases.
