Remove dark mode and fix boot splash HTML breakage.

Drop dark-mode toggle, fd-theme storage, and Tailwind dark variant to match sibling Ladill apps. Include boot splash in app-layout instead of regex middleware that truncated the body tag on Alpine x-init.

Co-authored-by: Cursor <cursoragent@cursor.com>

resources/css/app.css

@@ -1,6 +1,5 @@
 @import 'tailwindcss';
 @plugin '@tailwindcss/forms';
-@custom-variant dark (&:where(.dark, .dark *));
 
 @source '../../vendor/laravel/framework/src/Illuminate/Pagination/resources/views/*.blade.php';
 @source '../../storage/framework/views/*.php';