📝 **Task:** Implement `tenant_filter(rows, tenant_id)` returning only rows whose `tenant_id` matches. Then implement `audit_leaks(rows, tenant_id)` that returns the count of rows belonging to OTHER tenants — non-zero means a query forgot its filter. Print 4 results: filtered ids of t1, count of leaks-for-t1, filtered ids for t2, and audit on an already-clean list. 📋 Implement the function above. Tests run automatically. 💡 **Hint:** Re-read the theory if stuck.