Updates a user profile using a nested profile object. Users may update themselves. To update another user, the caller must be an organization admin and a full member of a shared, active workspace in that organization; the target may be a full or external member. Workspace-admin and field-specific permissions also apply. Manage custom user tags separately with PUT /workspaces/{workspaceId}/users/{userId}/user-tags/{userTagId}, using selectedOptions for one tag group at a time.