Keep a full-screen dialog's subtitle on a phone

The bar names the dialog there, so only the headline hides; the subtitle
used to disappear with it, and a subtitle without a title never showed.

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

tests/Feature/Components/OverlayTest.php

@@ -44,6 +44,17 @@ it('uses the surrounding Alpine scope without wire:model, and stays open when pe
         ->toContain('aria-label="Close"');
 });
 
+it('keeps a full-screen dialog\'s subtitle on a phone, where its bar carries the title', function () {
+    $html = (string) $this->blade('<x-modal title="Enable 2FA" subtitle="Scan the code" fullscreen>Text</x-modal>');
+
+    expect($html)
+        ->toMatch('/<h2 id="[^"]+-title" class="type-headline-sm max-sm:hidden">/')
+        ->toContain('<p class="type-body-md text-on-surface-variant mt-4 max-sm:mt-0">Scan the code</p>')
+        ->not->toContain('<div class="mb-4 max-sm:hidden">')
+        ->and((string) $this->blade('<x-modal title="Help" fullscreen>Text</x-modal>'))->toContain('<div class="mb-4 max-sm:hidden">')
+        ->and((string) $this->blade('<x-modal subtitle="Only a subtitle">Text</x-modal>'))->toContain('<p class="type-body-md text-on-surface-variant">Only a subtitle</p>');
+});
+
 it('slides a side sheet in from either edge, and is a pane from xl when asked', function () {
     expect((string) $this->blade('<x-drawer title="Details" with-close-button>Body</x-drawer>'))
         ->toContain('x-trap.inert.noscroll="open && ! wide"')