D from URL
        const urlParams = new URLSearchParams(window.location.search);
        const conversationId = urlParams.get('conv_id');
        
        async function joinConversation() {
            console.log('joinConversation() called');
            
            if (!conversationId) {
                showError('Invalid join link - no conversation ID provided');
                return;
            }
            
            // Check if user is authenticated
            const authToken = localStorage.