refactor: Improve toast notification rendering and event handling

- Refactored the ShowToastJS function to create toast elements using DOM methods for better safety and maintainability.
- Changed the event listener for the 'showToast' event from document.body to document for improved event handling.
- Ensured that the message content is set using textContent to prevent potential XSS vulnerabilities.

static/js/app.js

@@ -449,7 +449,7 @@ function enhanceMobileForms() {
 
 
 // Listen for custom 'showToast' event triggered by HX-Trigger
-document.body.addEventListener('showToast', function(event) {
+document.addEventListener('showToast', function(event) { // Changed from document.body
   // Debug logs removed
   if (event.detail && event.detail.message && event.detail.type) {
     // Call the globally defined showToast function from toast_js.templ