Draw the alert's dismiss button from the interaction classes

Plan step 36 ("Interaction is the shared classes", the user, 2026-09-14).
The dismiss button hand-rolled md-state-layer, md-focus-ring and
md-touch-target, and alert.css's own header said so; it now renders the
classes and keeps only its own size, offset and colour.

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

resources/views/components/alert.blade.php

@@ -15,8 +15,8 @@
      something the person just did (ACT-36). M3 publishes no banner; the nearest thing it does
      publish, the snackbar, says polite and never assertive.
 
-     Drawn by resources/css/components/alert.css from `data-md-alert` and `data-md-color`; no
-     class list. --}}
+     Drawn by resources/css/components/alert.css from `data-md-alert` and `data-md-color`; the
+     dismiss button carries only the foundation's interaction classes. --}}
 
 @props([
     'title' => null,
@@ -63,7 +63,7 @@
     </div>
 
     @if ($dismissible)
-        <button type="button" data-md-alert-dismiss aria-label="{{ __('Dismiss') }}" x-on:click="shown = false">
+        <button type="button" class="md-state-layer md-focus-ring md-touch-target" data-md-alert-dismiss aria-label="{{ __('Dismiss') }}" x-on:click="shown = false">
             <x-livewire-material::icon name="close" size="20" />
         </button>
     @endif