GET List Pattern Categories​
Return the distinct category names currently in use, sorted alphabetically.
This is derived from the patterns themselves, not from the stored category records — a category created via POST /email-patterns/categories does not appear here until at least one pattern uses it. The result is a flat array of strings with no ids; use the ids from wp_pattern_category when you need them.
Required capability: fcrm_read_emails or fcrm_manage_emails — which one applies depends on the action being performed.
Enforced by EmailPatternPolicy::verifyRequest(), the policy default for this route group.
Authorizations​
WordPress Application Passwords — use Basic auth with your WordPress username and an application password in the format: username:application_password
Responses​
Category names in use.