Close a full-screen search back into its bar or icon, bar and view together

`fullScreen` followed `open`, so the moment a full-screen search closed,
`data-md-full-screen` went with it: the fixed header bar went back to its
resting pill — or to `display: none`, behind the search icon — and the
view, still fading out under Alpine's hold, dropped to the docked layout
for its exit. In every engine the bar vanished on the first frame while
the view went on fading somewhere else.

search.js: a close from full screen now `hold()`s the layout — `leaving`
keeps `fullScreen`, and with it `data-md-full-screen`, the back arrow and
the fixed bar, for the view's own closing duration, read from its
computed style a frame on (zero under reduced motion); reopening lets a
pending end go by. search.css fades the header bar out with the view on
the view's spring and keeps the root above the page while it leaves,
and the icon trigger's bar stays displayed until the layout settles. The
focus trap now binds to `open && fullScreen`, so it still lets go at the
close and its return of focus lands inside RETURN_GUARD_MS rather than
reopening the view at the end of the exit.

PickingTest samples both exits in the page — the icon trigger, and the
bar trigger on a compact window — for a moment where the root is still
full screen with a fixed bar and both bar and view part-way through their
fade, then checks the settled layout and focus back on the icon or the
field; both fail on the previous code in Chrome, Firefox and Safari. The
tests wait for the entry's own transitions first: Firefox reads a
transition's end value until its next refresh tick.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/Feature/Components/SearchTest.php

@@ -114,7 +114,9 @@ it('draws the bar and the view from its stylesheet, at M3\'s widths', function (
     expect($css)->toContain('@layer material.components')
         ->toMatch('/\\[data-md-search\\] \\{\\s*--search-height: 56px;[^}]*--search-open-width: 720px;/')
         ->toContain('[data-md-search][data-md-full-screen] [data-md-search-view] {')
-        ->toContain("[data-md-search][data-md-trigger='icon']:not([data-md-open]) [data-md-search-bar] {")
+        ->toContain("[data-md-search][data-md-trigger='icon']:not([data-md-open], [data-md-full-screen]) [data-md-search-bar] {")
+        // Leaving full screen, the header bar fades with the view instead of going on the first frame.
+        ->toContain('[data-md-search][data-md-full-screen]:not([data-md-open]) [data-md-search-bar] {')
         ->not->toMatch('/\\d(?:\\.\\d+)?rem/')
         ->and((string) file_get_contents(__DIR__.'/../../../resources/css/all.css'))->toContain("@import './components/search.css';");
 });