feat: add SortableJS and wrap kanban initialization in a robustness handler for delayed script loading

resources/views/projects/show.blade.php

@@ -15,6 +15,9 @@
     <!-- Tailwind CSS -->
     <script src="https://cdn.tailwindcss.com"></script>
     
+    <!-- Sortable JS for Drag and Drop -->
+    <script src="https://cdn.jsdelivr.net/npm/sortablejs@1.15.0/Sortable.min.js"></script>
+    
     <script>
         tailwind.config = {
             darkMode: 'class',
@@ -860,6 +863,12 @@ gantt
         }
 
         // Sortable.js Drag and Drop Setup for 4 Kanban Columns
+        function initKanbanSortable() {
+            if (typeof Sortable === 'undefined') {
+                setTimeout(initKanbanSortable, 100);
+                return;
+            }
+
             document.querySelectorAll('.kanban-drop-zone').forEach(zone => {
                 new Sortable(zone, {
                     group: 'kanban-board',
@@ -906,6 +915,13 @@ gantt
                     }
                 });
             });
+        }
+
+        if (document.readyState === 'loading') {
+            document.addEventListener('DOMContentLoaded', initKanbanSortable);
+        } else {
+            initKanbanSortable();
+        }
 
         // AJAX Module Status Toggle Handler
         function setModuleStatusAjax(moduleId, status) {