Sky Addons <= 3.3.2 - Authenticated (Author+) Stored Cross-Site Scripting via Custom Script

The Sky Addons plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `sky-custom-scripts` custom post type in all versions up to, and including, 3.3.2. This is due to the custom post type being registered with `capability_type => 'post'` and `show_in_rest => true`, combined with insufficient input sanitization on the `sky_script_content` meta field and lack of output escaping when rendering scripts on the frontend. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts via the REST API that execute on every frontend page for all site visitors.