Update email sync loader and changes to use system actor instead of user actor. This ensures email sync always works regardless of user permissions.
Extract actor from changeset context and pass it to all email sync loader functions to ensure proper authorization when loading linked users and members.
Document public API functions with @doc for better tooling support: - EmailSync Changes: sync_user_email_to_member, sync_member_email_to_user - Validations: email_not_used_by_other_member, email_not_used_by_other_user - Senders: send_new_user_confirmation_email, send_password_reset_email