Two findings from the retrospective review of 394cccfb..e24c272e (#34).
listmonk_reconcile() deleted subscribers with no members row outright. That
destroyed the subscriber's consent/unsubscribe history, and a stray test account
is indistinguishable from a real person who subscribed outside the portal. Both
classes now leave the list the same way — PUT {"lists": []} — and the record is
kept as a suppression marker; nothing is purged automatically. The summary log
line reports counts by reason instead of subscriber addresses. Subscriber
pagination also gains a short-page fallback so a missing `total` cannot truncate
the reconcile at page 1.
reconcile_memberships() called fetch_members() unguarded, so the documented
fail-safe — skip reconciliation rather than deactivate everyone missing from a
partial list — was unreachable: since fetch_members() now raises, the sweep
returned a 500 instead of {"status": "skipped"}. It now catches the failure and
returns reason "member_fetch_failed". The two webhook call sites are left
unguarded on purpose: a payment webhook should fail loudly so OC retries it, and
it self-heals.
Refs #34