When a dropdown is open, block Tab to avoid navigating away.

Under Windows, dropdowns cannot be tabbed off of. They are only closed by either selecting an item or pressing Escape.

assets/js/app.js

@@ -87,6 +87,8 @@ Hooks.Menu = {
       let menuItems = this.menuItems()
       this.deactivate(menuItems)
       this.activate(menuItems.indexOf(this.activeItem) - 1, menuItems.length - 1)
+    } else if (e.key == "Tab") {
+      e.preventDefault()
     }
   }
 }