Fix CSRF token not found error on guest pages (login/register)

The app layout renders separate head blocks for auth vs guest users.
The guest block was missing the <meta name="csrf-token"> tag that
app.js reads to set the axios X-CSRF-TOKEN header, causing a console
error on the login and register pages. Add the meta tag to the guest
head to match the authenticated head block.

resources/views/layouts/app.blade.php

@@ -68,6 +68,7 @@
 	<meta charset="utf-8">
 	<meta http-equiv="X-UA-Compatible" content="IE=edge">
 	<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
+	<meta name="csrf-token" content="{{ csrf_token() }}">
 	<meta name="mobile-web-app-capable" content="yes">
 
 	<title>{{ $title ?? config_cache('app.name', 'Pixelfed') }}</title>