Izvlači iz: newsletter_members (subscribed=1 i nije unsubscribed) + newsletter_ebook_subscribers.
Dedup radi po email_norm. Svako “Sačuvaj” pravi novi mailing_id i novi queue snapshot.
newsletter_members.last_sent_at/send_count/last_mailing_id se update-uje,
a za ebook: last_sent_at/send_count.