Subscription page: the one-window model can't express prepaid/postpaid, calendar or
anniversary anchoring, grace or an expiry notice; and renewal is OFF-BOOK today (a PUT
that appends no payment — the same hole closed for the first sale on 2026-06-20).
Designed: plan billing rule, per-day pricing so both anchors share one formula, open-
ended agreement, subscription_periods where each period is a ledger charge and a renewal
= paying the next period, one subscriptionAccess() gate function, expiry notice derived
not stored.
New decision page party-ledger: a counterparty sub-ledger for who-owes-whom across
modules — parties + signed charge / settlement / write_off events, balance derived never
stored, aging + statements + CSV; lands postpaid subscriptions, hotel guest-nights,
fleet washes on account, supplier/utility bills. Sub-ledger only: no bookkeeping, a
statement is not a fiscal invoice, parties per appliance. validation-sponsorship's
sponsor table marked superseded; open-questions #17; index.
Claude-Session: https://claude.ai/code/session_01FWncR69HgGPuei1dLrW3cU
