为当前用户在目标租户重新签发访问令牌；要求该用户在目标租户存在 active 成员关系
OK
Memberships lists every tenant the user can authenticate into, along with their role in each. Always populated (length 1 for users who only belong to their home tenant) so frontends can render a tenant switcher without a follow-up request. Serialised without omitempty so the field is always present as a JSON array (possibly empty) — the "always populated" contract relies on the server side guaranteeing a non-nil slice.