* refactor(captcha): update Cap backend to 2.0.0 API format
* feat(captcha): add Cap version config for 1.x/2.x compatibility
* fix(captcha): change Cap default version to 1.x for backward compatibility
* refactor(captcha): remove Cap 1.x compatibility, keep only 2.x support
* feat(captcha): update field names to Cap 2.0 standard - Site Key and Secret Key
* fix(captcha): update Cap field names in defaults configuration