Appending data to copied text when there's a copy action

add_nonce_to_copied_text.js

document.addEventListener('copy', function(event) {
    // Get the selected text
    var selectedText = window.getSelection().toString();
    
    // Generate a nonce (unique identifier)
    var nonce = 'my_unique_nonce';
    
    // Append the nonce to the selected text
    var modifiedText = selectedText + ' [Nonce: ' + nonce + ']';
    
    // Copy the modified text to the clipboard
    event.clipboardData.setData('text/plain', modifiedText);
    
    // Prevent the default copy behavior
    event.preventDefault();
});