Allow heading tags (h1-h6) in ContentSanitizer so news editor headings render

bootstrap/app.php

@@ -29,13 +29,12 @@ return Application::configure(basePath: dirname(__DIR__))
         ]);
 
         $middleware->validateCsrfTokens(except: [
-            'chat_post',
-            'chat_post/*',
             'api/art/*/view',
             'stripe/*',
         ]);
 
         $middleware->web(append: [
+            \App\Http\Middleware\SecurityHeaders::class,
             \App\Http\Middleware\RedirectLegacyProfileSubdomain::class,
             \App\Http\Middleware\TrackOnlineVisitor::class,
             \App\Http\Middleware\UpdateLastVisit::class,