Draw the dragged layer on a card that is not a row

Plan step 36 review of f04e31b3. The card rendered md-state-layer only
on a row, so a card the application marks data-md-dragged without being
a row, as the showcase's "A card being dragged" is, lost the 16% dragged
layer its old inset shadow drew and its header still promises. Every
card now renders the class, since the attribute arrives from script
after render, and card.css keeps the layer off a card that is neither a
row nor dragged. The divider under the header is matched as its child.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9

tests/Feature/Components/CardTest.php

@@ -46,9 +46,13 @@ it('passes row attributes through and renders the shared interaction classes for
         ->toContain('data-md-list-row')
         ->toContain('data-md-list-open')
         ->toContain('class="md-state-layer md-focus-ring"')
+        // Any card can be carried, so each draws the shared layer, which card.css keeps off one
+        // that is neither a row nor dragged.
         ->and((string) $this->blade('<x-card title="Share">Body</x-card>'))
-        ->not->toContain('md-state-layer')
-        ->not->toContain('md-focus-ring');
+        ->toContain('class="md-state-layer"')
+        ->not->toContain('md-focus-ring')
+        ->and(ComponentStylesheet::read('card')->declarations('[data-md-card]:not([data-md-list-row], [data-md-dragged])::before'))
+        ->toBe(['display' => 'none']);
 });
 
 it('makes a directly actionable card the one tab stop, named by its title', function () {