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/svg/shapes/square.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" fill="currentColor"><path d="M89.6 89.6C84.4 94.8 77.2 98 69.2 98C56.4 98 43.6 98 30.8 98C14.9 98 2 85.1 2 69.2C2 56.4 2 43.6 2 30.8C2 14.9 14.9 2 30.8 2C43.6 2 56.4 2 69.2 2C85.1 2 98 14.9 98 30.8C98 43.6 98 56.4 98 69.2C98 77.2 94.8 84.4 89.6 89.6Z"/></svg>