BetterDocs < 4.3.12 - Missing Authorization to Authenticated (Subscriber+) Unauthorized AI API Usage

Description

The BetterDocs plugin for WordPress is vulnerable to Missing Authorization in versions up to and including 4.3.11. This is due to a missing capability check in the generate_openai_content_callback() function, which relies solely on a nonce rather than verifying user permissions. This makes it possible for authenticated attackers, with subscriber-level access and above, to trigger OpenAI API calls using the site's configured API key with arbitrary user-controlled prompts, leading to unauthorized consumption of the site owner's paid AI API quota.