Add booking stack, client deploys, and back-office updates

- deploy/booking: shared Easy!Appointments stack with brand-matched
  wizard (flatpickr recolor, single-tenant provider hide, iframe
  auto-fit height reporter)
- deploy/clients: per-client isolated nginx compose stacks with
  _template scaffold, new-client.sh, and happynails live site
- deploy/backup: smb-db backup script
- n8n: booking-sync workflow; onboarding tweaks
- playbooks: lead-to-customer lifecycle + outreach
- templates: nail-studio landing previews
- backoffice: app/db/init/compose updates

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backoffice/docker-compose.yml

@@ -24,6 +24,7 @@ services:
     environment:
       DATABASE_URL: postgresql://smbcrm:${DB_PASSWORD}@smb-db:5432/smbcrm
       CRM_API_TOKEN: ${CRM_API_TOKEN}
+      ICS_TOKEN: ${ICS_TOKEN}
       SHEET_ID: ${SHEET_ID}
       GOOGLE_SA_JSON: /run/secrets/gcp-sa.json
     volumes: