# Phase 4.1 Verification Gate

**Document Status:** PASSED & VERIFIED  
**Phase:** 4.1 Core Commercial Sub-Ledger Foundation  
**Date:** September 4, 2026  

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## Gate Summary

Phase 4.1 has satisfied all technical, architectural, security, database constraint, and backward compatibility criteria.

### Verification Checklist
- [x] **Schema Integrity:** Migrations created for `invoices`, `invoice_lines`, `supplier_invoices`, `supplier_invoice_lines`, `credit_notes`, `credit_note_lines`, `payment_allocations`.
- [x] **Decimal Precision:** Money fields initialized as `decimal(15, 4)` and tax rates as `decimal(5, 2)`.
- [x] **Tenant Scopes:** `OrganizationScope` and `BusinessUnitScope` implemented across all new primary models.
- [x] **Cross-Tenant Guarding:** Boot hooks throw `CrossOrganizationException` when attempting cross-tenant record associations.
- [x] **Tenant Uniqueness:** Unique composite indexes enforced for `(business_unit_id, invoice_number)`, `(business_unit_id, internal_reference)`, and `(business_unit_id, credit_note_number)`.
- [x] **Backward Compatibility:** `payments.order_id` and `supplier_payments.purchase_order_id` converted to nullable columns without breaking legacy Phase 3 test cases.
- [x] **Business-Agnostic Core:** Zero business extension terms present in `app/Domains/Core/`.
- [x] **No GL Posting:** Financial Service remains untouched; zero journals posted during Phase 4.1.
- [x] **Test Baseline:** 162 / 162 tests passed (280 assertions, 0 failures, 0 errors).

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## Sign-Off

Phase 4.1 Commercial Sub-Ledger Foundation is formally APPROVED.