Banner QR routes to a broker WhatsApp chat in office hours, Calendly off-hours, and 'similar listings nearby' once the unit sells.
Lifecycle-aware: active sale → live broker. Sold → 'we have 5 similar' lead form. Out of hours → Calendly self-book. The €€ vinyl banner stays up; only the QR's destination changes.
Free tier includes 1 permanent QR and the recovery key — upgrade the slot with the exact modules this case uses whenever you need them.