Cover six actions/communication behaviours the browser suite missed

Plan step 36's handoff listed six behaviours no browser test exercised
yet:
- FieldsTest: <x-select>'s open list uses the customizable picker
  (appearance: base-select) where the browser supports it, drawn as
  M3's 48px-row menu.
- CommunicationTest: a two-line snackbar's action stays on the
  title's row from 600px, only wrapping under it below that
  (toast.css's [data-md-toast-wrap]).
- ActionsTest: a disabled menu item reached by the keyboard withholds
  its state layer (interaction.css's [aria-disabled="true"] rule).
- DataTest: a paginator's page step shows md-focus-ring's outline on
  keyboard focus, alongside its already-tested 48px target.
- CommunicationTest: a transient rich tooltip stays open 1.5s after
  focus leaves rather than closing at once (rich-tooltip.js's
  LEAVE_GRACE_MS).
- ActionsTest: an xs or sm group segment takes a press at its 48px
  edge, past its drawn size, now that the target comes from the
  shared md-touch-target class rather than a rule of its own.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9

tests/Browser/DataTest.php

@@ -132,3 +132,18 @@ it('draws each page step 40px and lets it be pressed anywhere in its 48px target
         ->assertScript("(() => { const step = document.querySelector('[data-md-pagination] button[aria-label=\"Go to page 2\"]'); const box = step.getBoundingClientRect(); return box.width === 40 && box.height === 40 && document.elementFromPoint(box.left + box.width / 2, box.top - 3) === step; })()")
         ->assertScript("getComputedStyle(document.querySelector('[data-md-pagination] [aria-current=\"page\"]')).backgroundColor !== 'rgba(0, 0, 0, 0)'");
 });
+
+it('shows a page step\'s keyboard focus ring, from md-focus-ring', function () {
+    $step = "document.querySelector('[data-md-pagination] button[aria-label=\"Go to page 2\"]')";
+
+    $page = dataProbe();
+
+    // A key press first puts the browser in keyboard modality, as a keyboard user would be —
+    // Firefox only counts a scripted focus as :focus-visible after one.
+    $page->keys('#by-name [data-md-sort-header-button]', 'Tab');
+    $page->script("{$step}.focus()");
+
+    $page->assertScript("document.activeElement === {$step}")
+        ->assertScript("getComputedStyle({$step}).outlineStyle === 'solid'")
+        ->assertScript("getComputedStyle({$step}).outlineWidth === '3px'");
+});