fix(ui): reserve scrollbar space and animate event multiselect

Always reserve vertical scrollbar space on base and v5 body
layouts to prevent content shift. Match notification event
multiselect panel open/close transitions to other listboxes.

resources/views/layouts/base.blade.php

@@ -95,7 +95,7 @@
 </head>
 @section('body')
 
-<body class="dark:text-inherit text-black">
+<body class="overflow-y-scroll dark:text-inherit text-black">
     <x-toast />
     <x-icon-tooltip />
     <script data-navigate-once>