fix(gui): move focus into a folder when it opens

Opening a folder called .focus({ preventScroll: true }) on a jQuery
object. jQuery's .focus() shorthand reads a lone non-function argument
as event DATA and binds a handler with it, so it never moved focus:
the folder opened modal over the grid with focus still on the tile
behind its scrim, where Tab walked away through the inert grid instead
of cycling inside the dialog — and the object it bound as a handler
threw a TypeError on that tile's every subsequent focus.

Focus the DOM node instead, as every other focus call in this file
already does.

src/gui/src/UI/Dashboard/TabApps.js

@@ -1319,7 +1319,14 @@ const TabApps = {
             input.focus();
             input.select();
         } else {
-            $overlay.find('.myapps-tile').first().focus({ preventScroll: true });
+            // The DOM node, not the jQuery wrapper: jQuery reads a lone
+            // object argument to .focus() as event DATA and binds a handler
+            // with it instead of moving focus — so the folder opened with
+            // focus still on the inert grid behind it (Tab then walked off
+            // through that grid, past this dialog's trap), and the bogus
+            // handler threw on the tile's every later focus.
+            const first = $overlay.find('.myapps-tile')[0];
+            if ( first ) first.focus({ preventScroll: true });
         }
     },