Implements BILLING.md. The architecture was sound -- snapshot-on-Due,
dated prices, asymmetric dry-run commands are all kept -- so this
fixes the three hardcoded assumptions rather than rewriting.
The real defect: grace ran from period_END, so an annual club used
the whole unpaid year plus 45 days (~410 days) before anything
switched it off. Grace now runs from the period START, and every
clock is per-plan.
- Tier -> Plan (+ TierPrice -> PlanPrice, and every FK). Migration
0004 is hand-written: run non-interactively, makemigrations emits
DeleteModel+CreateModel and drops every price, subscription and
due. Its two RemoveConstraints must come first, or SQLite's
table-rebuild tries to render a constraint over a just-renamed
column. Verified by round-tripping real rows through it.
- Plan gains duration_months / renewal_lead_days / grace_days /
is_trial, with CheckConstraints and a matching clean() so the form
reports an impossible plan instead of 500ing on IntegrityError.
- Existing dues keep their stored grace_until. Re-deriving it would
put the date in the past for every open annual period and archive
the entire paying customer base on the next --commit run.
- Trials take their length from the trial plan's own duration_months;
start_trial() loses its trial_months argument.
- New BillingNotice service drives a club-facing warning: every level
on the dashboard, and on every management page once urgent.
- send_billing_reminders emails club admins, once per escalation
level so a daily cron is not a daily email. SMTP settings are
env-driven and provider-agnostic; the backend defaults to console.
- Paying does not auto-restore an archived club -- the control panel
surfaces a Reactivate prompt instead, since a club can also be
archived by hand.
Bernard Siebens
fc6488ce55