Captcha verification

The Captcha verification module in AscensionBot — what it does and how to configure it.

An alternative verification method alongside the button gate: new members get a random math problem in a modal and 3 tries to solve it. It filters out bots and automated accounts far more effectively than a simple button click, while still taking a real human only seconds to clear. Success grants the entry role, and repeated failure can optionally trigger an automatic kick.