Keep the search view closed when its focus comes back late

On a slow machine Escape could close the full-screen search and have it
open again for good. A close hands focus back to the input — Escape does,
and so does the view's focus trap as it lets go — and `focused()` told
that return from someone coming to search by a 250ms wall-clock window.
Both returns run on frames, and a runner painting a few frames a second
took longer than that, so the returning focus opened the view again. A
`returning` flag now covers the close until the hand-back has actually
run, on the same frame, and the constant is gone.

`hold()` times the full-screen layout from the exit's own duration token,
the one Alpine's x-transition holds `display` for, instead of waiting a
frame or two for the exit's transitions to appear: `getAnimations()` is
empty both before an engine creates them and after they end, and a loaded
engine can leave a second between frames.

The browser tests were racing the same slow machine, reproduced in a
Linux container like the runner, with its Playwright Firefox and
WebKitGTK and two cores kept busy:

- The browser plugin retries every script and action with a one-second
  attempt until the budget runs out. An in-page sleep longer than that
  only ever passed on the last attempt, which is where the 47-50s tests
  came from, and a script that clicks was run again against a page that
  had moved on. `onceInPage()` runs such a script once however often it
  is retried; the long sleeps are plain retried conditions now.
- Under load WebKitGTK paints no frame while a tight setTimeout loop
  runs, so a sample loop saw the start value and then nothing.
  `caughtMidExit()` samples on animation frames, for 2.5s.
- "No animations running" is also true before an opening transition
  exists, so a close could be sampled from a scrim at 4% opacity.
  `settled()` waits two frames before it asks.

The workflow no longer uploads failure screenshots: Gitea's artifact
service timed out on every attempt, two minutes per red run, and the job
logs are readable without it.

Feature 1159 passed. Browser 299 passed on Chrome, Firefox and WebKit on
macOS, and on Firefox and WebKitGTK in the Linux container under load,
twice each.

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

tests/Browser/NavigationTest.php

@@ -647,37 +647,15 @@ it('reads expanded while a modal rail is open over the page, and collapsed once
 });
 
 /**
- * Closes a rail with the given script and reports whether, sampling every few ms in the page
- * itself, it was ever caught part-way: the whole close in one round trip, since a separate
- * `script` and `assertScript` apiece already take as long as the 200ms exit (see ContainmentTest's
- * scrim fades). Called after slowMotion(), so the panel's own close — on the emphasized-accelerate
- * easing, which stays close to its start for a good part of its run — still needs a couple of
- * seconds of that stretched exit before its position has moved the couple of pixels `$partWay`
- * looks for; 2000ms (400 × 5ms) covers that with room to spare, short of the full exit ending.
+ * Closes a rail with the given script and reports whether, sampling once a frame in the page
+ * itself, it was ever caught part-way (caughtMidExit() in tests/Pest.php). Called after
+ * slowMotion(), so the panel's own close — on the emphasized-accelerate easing, which stays close
+ * to its start for a good part of its run — has moved the couple of pixels `$partWay` looks for
+ * within a handful of the stretched exit's frames.
  */
 function caughtMidClose(mixed $page, string $close, string $partWay): bool
 {
-    return $page->script(<<<JS
-        (async () => {
-            {$close}
-
-            for (let i = 0; i < 400; i++) {
-                if ({$partWay}) return true
-                await new Promise((resolve) => setTimeout(resolve, 5))
-            }
-            return false
-        })()
-        JS) === true;
-}
-
-/**
- * Opened and done opening: no transition left on the element. Firefox creates a transition on its
- * next refresh tick, so straight after the change its computed style already reads the end value
- * while the entry has not begun, and a close then would start from where the entry did.
- */
-function settled(string $element): string
-{
-    return "{$element}.getAnimations().length === 0";
+    return $page->script(caughtMidExit($close, $partWay)) === true;
 }
 
 /** Still drawn, and strictly between resting at the window's edge and gone past it. */
@@ -690,7 +668,8 @@ it('slides the compact rail out on close, rather than making it vanish', functio
     $page = shellPage(599, 860)
         ->click('@shell-menu')
         ->assertScript(RAIL.".hasAttribute('data-md-open')")
-        ->assertScript(settled(RAIL_PANEL).' && Math.round('.RAIL_PANEL.'.getBoundingClientRect().left) === 0');
+        ->assertScript(settled(RAIL_PANEL))
+        ->assertScript('Math.round('.RAIL_PANEL.'.getBoundingClientRect().left) === 0');
 
     slowMotion($page);
 
@@ -710,7 +689,8 @@ it('slides a rail that hides when collapsed out on close, rather than making it
         ->assertScript("Math.round({$rail}.getBoundingClientRect().width) === 0")
         ->click('#open-hiding-rail')
         ->assertScript("{$rail}.hasAttribute('data-md-open')")
-        ->assertScript(settled($panel)." && Math.round({$panel}.getBoundingClientRect().left) === 0 && Math.round({$panel}.getBoundingClientRect().width) === 256");
+        ->assertScript(settled($panel))
+        ->assertScript("Math.round({$panel}.getBoundingClientRect().left) === 0 && Math.round({$panel}.getBoundingClientRect().width) === 256");
 
     slowMotion($page);
 
@@ -727,7 +707,8 @@ it('fades a modal rail\'s scrim out on close while the rail stands collapsed in
     $page = railValueProbe('modal', 1000)
         ->click('#open-rail')
         ->assertScript(RAIL.".hasAttribute('data-md-open')")
-        ->assertScript(settled($scrim)." && getComputedStyle({$scrim}).opacity === '1'");
+        ->assertScript(settled($scrim))
+        ->assertScript("getComputedStyle({$scrim}).opacity === '1'");
 
     $fading = "(getComputedStyle({$scrim}).display !== 'none' && parseFloat(getComputedStyle({$scrim}).opacity) > 0.02 && parseFloat(getComputedStyle({$scrim}).opacity) < 0.98)";