10-task plan covering multi-tenant infrastructure: - Tenant DB provisioning from template (21 tables) - PIN auth with JWT, rate limiting, lockout - Permission system (owner/admin/cashier/warehouse/accountant) - Audit logging (insert-only) - Config: branches, employees, theming - Migration runner for versioned schema updates Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>