fix: improve error handling in AddEmployee by logging the root cause and displaying it in the error dialog

Author: pitzzahh

src/main/java/ui/AddEmployee.java

@@ -463,11 +463,11 @@ private void JButtonAddEmployeeActionPerformed(java.awt.event.ActionEvent evt) {
                                 JOptionPane.showMessageDialog(this, "Employee created successfully", "Success", JOptionPane.INFORMATION_MESSAGE);
                             });
                 }).exceptionally(throwable -> {
-                    log.error(throwable.getMessage(), throwable);
+                    log.error(throwable.getCause().getMessage(), throwable);
                     JButtonAddEmployee.setEnabled(true);
                     setProgressBarVisible(false);
                     Util.UI.setInteractionEnabled(jPanel3.getComponents(), true, () -> JButtonAddEmployee.setEnabled(true));
-                    JOptionPane.showMessageDialog(this, throwable.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
+                    JOptionPane.showMessageDialog(this, throwable.getCause().getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
                     return null;
                 });
     }//GEN-LAST:event_JButtonAddEmployeeActionPerformed