<ul><li>Created Documentation/Billing_System/ with 9 files covering full billing system discovery</li><li>Documented all billing-related DB tables with schema, row counts, and status (confirmed, active, dead)</li><li>Mapped all billing codebase files, classes, and methods in BillingService.php, billing.class.php, StripeService.php, cron/index.php</li><li>Documented execution flows: invoice generation, payment recording, usage tracking, service subscriptions</li><li>Identified all CRITICAL/HIGH/MEDIUM risks including missing stripe_subscriptions table causing cron crash, 167 subscriptions with 4 invoices, dual billing systems with no reconciliation</li><li>Gap analysis against target billing model (modules, services, API/AI, invoice, subscription engine)</li><li>Recommended architecture outline with new tables (billing_subscription_items, billing_tax_rules, billing_usage_events, billing_subscription_audit) and phased migration plan</li><li>Next steps with immediate action queries, top 10 files, top 10 tables, and 10 architect decisions required before redesign</li></ul>