Fix Paystack Fullscreen permission policy for Inline iframes.

Pre-set allow=fullscreen on Paystack iframes before navigation (createElement
hook + MutationObserver on allow/src/id), re-apply if Paystack overwrites
allow, and send Permissions-Policy HTTP headers so checkout.paystack.com can
use fullscreen inside the in-app sheet.

bootstrap/app.php

@@ -25,6 +25,7 @@ return Application::configure(basePath: dirname(__DIR__))
         $middleware->web(append: [
             \App\Http\Middleware\InjectBootSplash::class,
             \App\Http\Middleware\SetActingAccount::class,
+            \App\Http\Middleware\PaystackPermissionsPolicy::class,
         ]);
         $middleware->alias([
             'platform.session' => \App\Http\Middleware\EnsurePlatformSession::class,