Add the Material 3 Expressive foundation

Colour, shape, type, elevation and motion as tokens and Tailwind
utilities; `php artisan material:scheme`, which generates an app's colour
roles with Google's material-color-utilities (spec 2025); the theme head
script with light, dark and system and its Alpine store; Google Sans Flex;
every Material Symbol (4,135, outlined and filled) drawn by <x-icon>
without blade-icons; all 35 M3 Expressive shapes, ported from androidx, as
<x-shape>; the x-figure directive; the Toasts concern; DesignGuard for
applications' tests; and a showcase with every token, both themes side by
side and an icon search.

Colour utilities are `@theme inline`, so a section with its own
data-theme repaints; without it they resolve once on :root.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V9NnLxnPp8vaaurb3Z1MFy

resources/views/showcase/index.blade.php

@@ -1,12 +1,16 @@
 @extends('livewire-material::showcase.layout')
 
 @section('content')
-    <main class="mx-auto max-w-5xl px-4 py-10">
-        <h1 class="text-3xl">Livewire Material</h1>
-
-        <p class="mt-2">
-            Every component, in every variant, colour, size and state, in this application's own scheme.
-            Sections appear here as the components land.
+    <main class="mx-auto max-w-6xl space-y-16 px-4 py-10">
+        <p class="max-w-3xl type-body-lg text-on-surface-variant">
+            Every token and component, in this application's own scheme. Components appear here as they land.
         </p>
+
+        @include('livewire-material::showcase.sections.colour')
+        @include('livewire-material::showcase.sections.type')
+        @include('livewire-material::showcase.sections.shape')
+        @include('livewire-material::showcase.sections.elevation')
+        @include('livewire-material::showcase.sections.motion')
+        @include('livewire-material::showcase.sections.icons')
     </main>
 @endsection