Enhance file transfer capabilities by introducing support for multiple source paths and recursive directory transfers in FileController and LocalFileService. Updated TransferRequest to accommodate new fields, improved error handling, and refined UI interactions in app.js for better user experience during file operations.

src/main/resources/static/index.html

@@ -171,7 +171,8 @@
         </div>
     </div>
 
-    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/js/bootstrap.bundle.min.js"></script>
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/js/bootstrap.bundle.min.js"
+            onerror="this.onerror=null;var s=document.createElement('script');s.src='https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.3.0/js/bootstrap.bundle.min.js';document.body.appendChild(s);"></script>
     <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
     <script src="js/app.js"></script>
 </body>