Add a search to the showcase

A search app bar looks through every section, example and component,
opens the section, or the example at its anchor on its page, and is
reached from anywhere with / or Ctrl+K. Section pages now carry their
own heading.

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

tests/Browser/ShowcaseTest.php

@@ -19,3 +19,37 @@ it('moves between sections through the rail and the next-section link, keeping t
         ->assertScript("location.pathname.endsWith('/material/menus')")
         ->assertNoJavaScriptErrors();
 });
+
+it('finds a component from anywhere and opens its section', function () {
+    $page = visit('/material/buttons')->waitForEvent('networkidle')
+        ->assertScript("document.readyState === 'complete' && typeof window.Alpine !== 'undefined' && typeof window.Livewire !== 'undefined'");
+
+    $page->keys('#content', '/')
+        ->assertScript("document.activeElement.id === 'showcase-search'");
+
+    $page->type('#showcase-search', 'datepicker')
+        ->assertSeeIn('[data-search-view]', '<x-datepicker>');
+
+    $page->keys('#showcase-search', 'Enter')
+        ->assertScript("location.pathname.endsWith('/material/pickers')")
+        ->assertScript("document.title === 'Date pickers · Livewire Material'");
+});
+
+it('opens an example on another page at the example', function () {
+    $page = visit('/material')->waitForEvent('networkidle')
+        ->assertScript("document.readyState === 'complete' && typeof window.Alpine !== 'undefined' && typeof window.Livewire !== 'undefined'");
+
+    $page->click('#showcase-search')
+        ->type('#showcase-search', 'split button')
+        ->click('[data-showcase-result]:has-text("Example")')
+        ->assertScript("location.pathname.endsWith('/material/buttons') && location.hash.startsWith('#example-')")
+        ->assertScript('(() => { const box = document.getElementById(decodeURIComponent(location.hash.slice(1))).getBoundingClientRect(); return box.top >= 0 && box.top < innerHeight; })()');
+});
+
+it('says so when nothing matches', function () {
+    visit('/material')->waitForEvent('networkidle')
+        ->assertScript("document.readyState === 'complete' && typeof window.Alpine !== 'undefined' && typeof window.Livewire !== 'undefined'")
+        ->click('#showcase-search')
+        ->type('#showcase-search', 'zzzz')
+        ->assertSeeIn('[data-search-view]', 'Nothing matches');
+});