Resolve the package's own components through its namespace

Package views now write <x-livewire-material::button>, so a configured
prefix (which Blade spells <x-m::button>) and an application component
of the same name can no longer break or shadow them. The showcase
rewrites its examples to the configured prefix. Adds the README, and
waits for the adaptive rail to hear a resize before the navigation
tests press its menu button.

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

tests/Browser/NavigationTest.php

@@ -15,7 +15,10 @@ function navigationReady(mixed $page): mixed
 
 function shellPage(int $width = 1280, int $height = 900, string $path = '/material/shell'): mixed
 {
-    return navigationReady(visit($path)->resize($width, $height));
+    // The window is resized after the page starts loading, and an adaptive rail hears of the new
+    // width from a media query's change event, which can arrive after the first key press.
+    return navigationReady(visit($path)->resize($width, $height))
+        ->assertScript("window.eval(\"(() => { const rail = document.querySelector('[data-navigation-rail]'); return ! rail || rail.dataset.navigationRail !== 'adaptive' || Alpine.\$data(rail).wide === window.matchMedia('(min-width: 64rem)').matches; })()\")");
 }
 
 /**