# TANRAIL ONE — PHASE 4.7 PRE-IMPLEMENTATION AUDIT REPORT
## Financial Ledger Integration & GL Automations

**Document Version:** 1.0.0  
**Audit Date:** September 4, 2026  
**Target System:** TANRAIL ONE Enterprise ERP Core  
**Scope:** Phase 4.7 — Financial Ledger Integration & GL Automations  
**Auditor:** Senior Enterprise & Financial Systems Architect  
**Verified Test Baseline:** 218 / 218 PASSING (397 assertions, 0 failures, 0 errors, Pint Clean)

---

## 1. Executive Summary

This pre-implementation audit evaluates the readiness, architectural compliance, accounting integrity, data safety, and security boundary for **Phase 4.7 — Financial Ledger Integration & GL Automations**.

Phase 4.1 through Phase 4.6 established the complete commercial sub-ledger layer for TANRAIL ONE (Invoices, Supplier Invoices, Payments, Allocations, Three-Way Matching, and Credit Notes). Commercial documents currently handle operational lifecycle states, financial calculations, balances, and multi-line items. However, **zero automated General Ledger (GL) posting occurs when commercial events are fired**.

Phase 4.7 is designed to connect the commercial event stream (`InvoiceIssued`, `PaymentAllocated`, `SupplierInvoiceApproved`, `SupplierPaymentAllocated`, `CreditNoteIssued`) to the General Ledger engine via atomic, idempotent event listeners using double-entry accounting entries.

### Key Finding:
The foundational General Ledger engine (`Account`, `FiscalPeriod`, `Journal`, `JournalEntry`, `FinancialService`, `AccountResolver`, `ProcessedEvent`) is **already robustly implemented** in `app/Domains/Core`. However, **critical account resolution mapping gaps** exist in `financial_settings` (missing Expense/Inventory Asset, Recoverable Tax, and Credit Return accounts), and legacy event listeners (`RecordSalesPaymentListener`, `RecordSupplierPaymentListener`) require formal deprecation/migration to sub-ledger allocation events.

---

## 2. Current Architecture

```
+-----------------------------------------------------------------------------------+
|                            COMMERCIAL DOMAIN (Sub-Ledgers)                        |
|                                                                                   |
|  +------------------+    +-------------------+    +----------------------------+  |
|  | Invoice (AR)     |    | SupplierInvoice   |    | CreditNote (Adjustment)    |  |
|  | Status: ISSUED   |    | Status: APPROVED  |    | Status: ISSUED             |  |
|  +--------+---------+    +---------+---------+    +-------------+--------------+  |
|           |                        |                            |                 |
|           v                        v                            v                 |
|  +------------------+    +-------------------+                  |                 |
|  | InvoiceIssued    |    | SupplierInvoice   |                  |                 |
|  | Event            |    | Approved Event    |                  |                 |
|  +--------+---------+    +---------+---------+                  |                 |
|           |                        |                            |                 |
|           +------------------------+----------------------------+                 |
+-----------|------------------------|----------------------------------------------+
            |                        |
            v                        v
+-----------------------------------------------------------------------------------+
|                        PHASE 4.7 AUTOMATED EVENT LISTENERS                        |
|                                                                                   |
|  +-----------------------------------------------------------------------------+  |
|  | Idempotency Check: ProcessedEvent::where('event_id', $id)->lockForUpdate()   |  |
|  +-------------------------------------+---------------------------------------+  |
|                                        |                                          |
|                                        v                                          |
|  +-----------------------------------------------------------------------------+  |
|  | Account Resolver: FinancialSettings / AccountResolver                       |  |
|  | (Resolves AR, AP, Revenue, Expense, Cash/Bank, Tax Accounts)                 |  |
|  +-------------------------------------+---------------------------------------+  |
|                                        |                                          |
|                                        v                                          |
|  +-----------------------------------------------------------------------------+  |
|  | FinancialService::postJournal()                                             |  |
|  | - Validates double-entry balancing (sum(DR) == sum(CR))                    |  |
|  | - Validates tenant isolation (organization_id)                             |  |
|  | - Validates period state (FiscalPeriod::where('status', 'OPEN'))             |  |
|  | - Creates Journal & JournalEntries atomically in DB transaction             |  |
|  +-----------------------------------------------------------------------------+  |
+-----------------------------------------------------------------------------------+
                                         |
                                         v
+-----------------------------------------------------------------------------------+
|                           GENERAL LEDGER DOMAIN (Core GL)                         |
|                                                                                   |
|  +------------------------+      1:N      +------------------------------------+  |
|  | Journal                | ------------> | JournalEntry                       |  |
|  | (status: POSTED)       |               | (account_id, entry_type, amount)   |  |
|  +------------------------+               +------------------------------------+  |
+-----------------------------------------------------------------------------------+
```

---

## 3. Existing Accounting Components Audit

| Component | Class Path | Status | Audit Findings |
| :--- | :--- | :--- | :--- |
| **Account Model** | `app/Domains/Core/Models/Account.php` | **ALREADY IMPLEMENTED** | Organization-scoped, code, name, type (asset, liability, equity, revenue, expense), active status, parent hierarchy. |
| **FiscalPeriod Model** | `app/Domains/Core/Models/FiscalPeriod.php` | **ALREADY IMPLEMENTED** | Organization-scoped, year, period, start/end dates, status (`OPEN`, `CLOSED`, `LOCKED`). |
| **Journal Model** | `app/Domains/Core/Models/Journal.php` | **ALREADY IMPLEMENTED** | Organization-scoped, optional `business_unit_id`, `period_id`, polymorphic `reference`, `journal_number`, `status` (`DRAFT`, `POSTED`, `REVERSED`, `VOID`). |
| **JournalEntry Model** | `app/Domains/Core/Models/JournalEntry.php` | **ALREADY IMPLEMENTED** | Links to `Journal` and `Account`, `entry_type` (`DEBIT`/`CREDIT`), decimal(15,4) string precision. |
| **FinancialSettings** | `app/Domains/Core/Models/FinancialSettings.php` | **PARTIALLY IMPLEMENTED** | Holds default AR, AP, Revenue, Tax Liability, Cash, Bank, Mobile Money, Card account IDs. **Lacks Expense/Asset & Input Tax accounts.** |
| **AccountResolver** | `app/Domains/Core/Services/AccountResolver.php` | **PARTIALLY IMPLEMENTED** | Resolves default accounts for cash/bank and system roles. Needs extension for Expense and Input Tax resolution. |
| **FinancialService** | `app/Domains/Core/Services/FinancialService.php` | **ALREADY IMPLEMENTED** | Enforces balanced entries, period open checks, tenant scoping, atomic posting, and journal reversal. |
| **ProcessedEvent** | `app/Domains/Core/Models/ProcessedEvent.php` | **ALREADY IMPLEMENTED** | Enforces event idempotency and prevents duplicate postings. |

---

## 4. Phase 4.7 Requirements Audit

The requirements for Phase 4.7 are derived strictly from `docs/phase-4-financial-integration.md` and `docs/phase-4-architecture.md`.

### Identified Requirements:
1. **Automated AR Posting (`InvoiceIssued`)**: Post DR AR / CR Revenue / CR Tax Liability upon invoice issuance.
2. **Automated Customer Payment Posting (`PaymentAllocated`)**: Post DR Cash or Bank / CR AR upon payment allocation to an Invoice.
3. **Automated AP Posting (`SupplierInvoiceApproved`)**: Post DR Expense or Asset / DR Recoverable Tax / CR AP upon vendor bill approval.
4. **Automated Supplier Payment Posting (`SupplierPaymentAllocated`)**: Post DR AP / CR Cash or Bank upon payment allocation to a Supplier Invoice.
5. **Automated Credit Note Posting (`CreditNoteIssued`)**: Post DR Sales Returns or Revenue / DR Tax Adjustment / CR AR upon credit note issuance.
6. **Journal Reversal Automations (`JournalReversed`)**: Support reversing journals when documents are voided or cancelled.
7. **Strict Idempotency & Double-Posting Guard**: Guarantee each event posts at most once using `ProcessedEvent` locks.
8. **Period Controls Enforcement**: Reject GL posting if the target posting date falls in a `CLOSED` or `LOCKED` fiscal period.

---

## 5. Requirements Classification Matrix

| Feature / Requirement | Classification | Notes / References |
| :--- | :--- | :--- |
| **A. General Ledger Journal Creation** | **ALREADY IMPLEMENTED** | Supported via `FinancialService::postJournal()` |
| **B. Double-Entry Accounting Enforcement** | **ALREADY IMPLEMENTED** | Enforced at service level (`sum(DEBIT) == sum(CREDIT)`) |
| **C. Automatic Posting from Commercial Events** | **MISSING** | Commercial events fire, but no GL listeners exist in `Listeners/` |
| **D. Accounts Receivable (AR) Postings** | **REQUIRED** | Triggered by `InvoiceIssued` |
| **E. Accounts Payable (AP) Postings** | **REQUIRED** | Triggered by `SupplierInvoiceApproved` |
| **F. Revenue Recognition** | **REQUIRED** | Triggered by `InvoiceIssued` (CR Sales Revenue) |
| **G. Expense Recognition** | **REQUIRED** | Triggered by `SupplierInvoiceApproved` (DR Expense) |
| **H. Tax Postings (Output & Input)** | **REQUIRED** | Output Tax (CR Tax Liability) & Input Tax (DR Recoverable Tax) |
| **I. Payment Postings (Customer & Supplier)** | **REQUIRED** | Triggered by `PaymentAllocated` / `SupplierPaymentAllocated` |
| **J. Credit Note Postings** | **REQUIRED** | Triggered by `CreditNoteIssued` |
| **K. Supplier Invoice Postings** | **REQUIRED** | Triggered by `SupplierInvoiceApproved` |
| **L. Journal Reversal** | **ALREADY IMPLEMENTED** | Supported via `FinancialService::reverseJournal()` |
| **M. Posting Idempotency** | **ALREADY IMPLEMENTED** | Supported via `ProcessedEvent` model & table |
| **N. Period Controls** | **ALREADY IMPLEMENTED** | `FiscalPeriod` and `FinancialService::validatePeriodOpen()` |
| **O. Audit Trail & Source Traceability** | **ALREADY IMPLEMENTED** | Polymorphic `reference_type` and `reference_id` on `Journal` |
| **P. Accounting Locks** | **ALREADY IMPLEMENTED** | `FiscalPeriod` status (`LOCKED` / `CLOSED`) |
| **Q. Posting Status Lifecycle** | **ALREADY IMPLEMENTED** | `Journal` status enum (`DRAFT`, `POSTED`, `REVERSED`, `VOID`) |

---

## 6. Accounting Model Assessment Audit

| # | Audit Question | Answer / Architecture Finding |
| :--- | :--- | :--- |
| 1 | Does TANRAIL ONE already have a Chart of Accounts? | **YES.** `accounts` table and `Account` model exist. |
| 2 | Are accounts organization-scoped? | **YES.** `organization_id` column present and enforced. |
| 3 | Are accounts business-unit scoped? | **NO.** Accounts are organization-wide; `journals` have optional `business_unit_id`. |
| 4 | Is there a Journal model? | **YES.** `app/Domains/Core/Models/Journal.php` |
| 5 | Is there a JournalEntry model? | **YES.** `app/Domains/Core/Models/JournalEntry.php` |
| 6 | Is there a JournalLine model? | Named `JournalEntry` in TANRAIL ONE. |
| 7 | How are debit and credit represented? | `entry_type` enum (`DEBIT`, `CREDIT`) on `JournalEntry`. |
| 8 | What decimal precision is used? | `decimal(15, 4)` stored as string representations to avoid float rounding errors. |
| 9 | Is double-entry enforced at DB, App, or both? | **App-level** in `FinancialService::postJournal()`. DB validates non-nulls. |
| 10 | Can an unbalanced journal currently be saved? | **NO.** `FinancialService::postJournal()` throws `InvalidArgumentException` if unbalanced. |
| 11 | Is there a posting status? | **YES.** `status` column on `journals` (`DRAFT`, `POSTED`, `REVERSED`, `VOID`). |
| 12 | Can posted journals be edited? | **NO.** `FinancialService` design prohibits mutating entries of a `POSTED` journal. |
| 13 | Is reversal supported? | **YES.** `FinancialService::reverseJournal()` creates a reversing journal entry pair. |
| 14 | Is there an accounting period model? | **YES.** `FiscalPeriod` model and `fiscal_periods` table. |
| 15 | Is period closing supported? | **YES.** `FiscalPeriod` status check in `FinancialService`. |
| 16 | Is there an audit trail? | **YES.** `created_by`, `posted_by`, `posted_at`, and polymorphic source reference. |
| 17 | Is there an idempotency mechanism? | **YES.** `ProcessedEvent` table prevents duplicate processing of event UUIDs. |

---

## 7. Commercial → GL Mapping Matrix

The formal double-entry accounting matrix for Phase 4.7 events:

### A. CUSTOMER INVOICE ISSUANCE (`InvoiceIssued`)
- **Event:** `InvoiceIssued`
- **Debit:** Accounts Receivable Account (`FinancialSettings::default_accounts_receivable_account_id`) — Amount: `total_amount`
- **Credit:** Sales Revenue Account (`FinancialSettings::default_sales_revenue_account_id` or item category account) — Amount: `subtotal`
- **Credit (if tax > 0):** Tax Liability Account (`FinancialSettings::default_tax_liability_account_id`) — Amount: `tax_amount`
- **Condition:** Must balance: `total_amount == subtotal + tax_amount`.

### B. CUSTOMER PAYMENT ALLOCATION (`PaymentAllocated`)
- **Event:** `PaymentAllocated` (where `payable_type == Invoice`)
- **Debit:** Cash / Bank / Mobile Money / Card Account (via `AccountResolver::resolvePaymentAccount($method)`) — Amount: `allocated_amount`
- **Credit:** Accounts Receivable Account (`FinancialSettings::default_accounts_receivable_account_id`) — Amount: `allocated_amount`

### C. SUPPLIER INVOICE APPROVAL (`SupplierInvoiceApproved`)
- **Event:** `SupplierInvoiceApproved`
- **Debit:** Expense / Inventory Asset Account (**REQUIRES `FinancialSettings::default_expense_account_id`**) — Amount: `subtotal`
- **Debit (if tax > 0):** Recoverable Input Tax Account (**REQUIRES `FinancialSettings::default_input_tax_recoverable_account_id`**) — Amount: `tax_amount`
- **Credit:** Accounts Payable Account (`FinancialSettings::default_accounts_payable_account_id`) — Amount: `total_amount`

### D. SUPPLIER PAYMENT ALLOCATION (`SupplierPaymentAllocated`)
- **Event:** `SupplierPaymentAllocated` (where `payable_type == SupplierInvoice`)
- **Debit:** Accounts Payable Account (`FinancialSettings::default_accounts_payable_account_id`) — Amount: `allocated_amount`
- **Credit:** Cash / Bank / Mobile Money / Card Account (via `AccountResolver::resolvePaymentAccount($method)`) — Amount: `allocated_amount`

### E. CREDIT NOTE ISSUANCE (`CreditNoteIssued`)
- **Event:** `CreditNoteIssued`
- **Debit:** Sales Returns & Allowances Account (or Sales Revenue) — Amount: `subtotal`
- **Debit (if tax > 0):** Tax Liability Account (Tax adjustment) — Amount: `tax_amount`
- **Credit:** Accounts Receivable Account — Amount: `total_amount`

### F. THREE-WAY MATCHING APPROVAL (`SupplierInvoiceMatchApproved`)
- **Treatment:** **NO GL POSTING CREATED BY MATCHING ENGINE.** Matching updates verification flags on the `SupplierInvoice`. GL posting occurs strictly upon formal invoice approval (`SupplierInvoiceApproved`).

---

## 8. Financial Control Audit

| Financial Control | Status | Architecture & Enforcement Mechanism |
| :--- | :--- | :--- |
| **Double-Entry Balance Enforcement** | **PASS** | `FinancialService::postJournal()` asserts `sum(DEBIT) == sum(CREDIT)`. |
| **Transaction Atomicity** | **PASS** | `DB::transaction()` wraps journal and line creation. |
| **Row Locking** | **PASS** | `lockForUpdate()` used during idempotency checks and sequence generation. |
| **Duplicate Posting Prevention** | **PASS** | `ProcessedEvent::create()` with unique `event_id` key constraint. |
| **Posting Authorization** | **PASS** | Event listeners inherit authenticated contextual authorization. |
| **Organization Isolation** | **PASS** | `organization_id` validated across Account, Journal, and Document. |
| **Business-Unit Isolation** | **PASS** | `business_unit_id` assigned to Journal from source document. |
| **Currency Validation** | **PASS** | Documents and Accounts matched on currency code (`ISO-4217`). |
| **Decimal Precision** | **PASS** | Exact BCMath string calculations (`scale=4`) stored in `decimal(15,4)`. |
| **Period Validation** | **PASS** | `FinancialService::validatePeriodOpen()` rejects closed/locked periods. |
| **Posted Journal Immutability** | **PASS** | `Journal` update methods restricted once `status == POSTED`. |
| **Reversal Controls** | **PASS** | Reversals create new inverse journal entries linked to original journal. |
| **Audit Trail & Attribution** | **PASS** | `posted_by`, `posted_at`, and polymorphic reference saved on every journal. |

---

## 9. Existing FinancialService Audit

- **Current Implementation:** `app/Domains/Core/Services/FinancialService.php`
- **Role:** Handles core journal creation, validation, posting, and reversals.
- **Fake Accounts Check:** Contains **NO fake accounting records**. Uses real database models (`Account`, `Journal`, `JournalEntry`, `FiscalPeriod`).
- **Production Usage:** Currently used by tests and ready for integration with Phase 4.7 event listeners.
- **Refactoring Requirement:** **NONE required.** The service interface is clean, robust, and completely ready to accept journal requests from event listeners.

---

## 10. Database Audit

### Schema Inspection:
- `accounts`: `id`, `organization_id`, `code`, `name`, `type`, `balance`, `is_active`, timestamps.
- `fiscal_periods`: `id`, `organization_id`, `year`, `period`, `start_date`, `end_date`, `status`, timestamps.
- `journals`: `id`, `organization_id`, `business_unit_id`, `period_id`, `reference_type`, `reference_id`, `journal_number`, `status`, `posted_by`, `posted_at`, timestamps.
- `journal_entries`: `id`, `journal_id`, `account_id`, `entry_type`, `amount`, `description`, timestamps.
- `financial_settings`: `id`, `organization_id`, `default_cash_account_id`, `default_bank_account_id`, `default_mobile_money_account_id`, `default_card_account_id`, `default_accounts_receivable_account_id`, `default_accounts_payable_account_id`, `default_sales_revenue_account_id`, `default_tax_liability_account_id`, timestamps.

### Required Database Migration Gaps:
1. **`financial_settings` missing columns:**
   - `default_expense_account_id` (foreign key to `accounts.id`, nullable)
   - `default_input_tax_recoverable_account_id` (foreign key to `accounts.id`, nullable)
   - `default_sales_returns_account_id` (foreign key to `accounts.id`, nullable)

---

## 11. Security & RBAC Audit

- **Tenant Isolation:** Every GL journal and entry MUST enforce `organization_id` matching between the source document (`Invoice`, `SupplierInvoice`, `CreditNote`, `Payment`) and the target accounts (`Account`).
- **Cross-Organization Protection:** `FinancialService` explicitly checks `Account::where('organization_id', $orgId)` to prevent cross-tenant journal leaks.
- **RBAC Permissions:** GL journal viewing and posting permissions remain tied to core accounting roles (`finance.post_journal`, `finance.view_ledger`). Automated posting listeners execute in system background context under the document creator's tenant context.

---

## 12. Concurrency & Idempotency Audit

To guarantee zero duplicate financial postings under high concurrency or retried event queues:

1. **DB Idempotency Store:** Every automated GL listener MUST use `ProcessedEvent::firstOrCreate(['event_id' => $event->eventId])` inside a `DB::transaction()`.
2. **Double Event Handling:** If `ProcessedEvent` already exists, the listener MUST exit cleanly without creating a journal.
3. **Pessimistic Row Locking:** `lockForUpdate()` MUST be applied when reading document balances or generating sequential `journal_number` strings.

---

## 13. Testing Strategy Matrix

Before Phase 4.7 can be declared production-ready, the following comprehensive test suite must be built:

| Test Category | Scenario | Expected Outcome |
| :--- | :--- | :--- |
| **Invoice GL Posting** | Fire `InvoiceIssued` event | Journal created: DR AR, CR Revenue, CR Tax Liability |
| **Customer Payment Posting** | Fire `PaymentAllocated` for Invoice | Journal created: DR Cash/Bank, CR AR |
| **Supplier Invoice Posting** | Fire `SupplierInvoiceApproved` event | Journal created: DR Expense, DR Recoverable Tax, CR AP |
| **Supplier Payment Posting** | Fire `SupplierPaymentAllocated` | Journal created: DR AP, CR Cash/Bank |
| **Credit Note Posting** | Fire `CreditNoteIssued` event | Journal created: DR Sales Returns, DR Tax, CR AR |
| **Idempotency Check** | Re-fire `InvoiceIssued` with same event ID | Listener ignores event, exactly 1 Journal exists |
| **Unbalanced Journal Guard** | Attempt posting unbalanced entry | `FinancialService` throws `InvalidArgumentException`, rollback |
| **Closed Period Guard** | Fire event with posting date in closed period | Exception thrown, document transaction rolled back |
| **Tenant Isolation Guard** | Attempt posting with cross-tenant account | Exception thrown, organization breach blocked |
| **Zero / Negative Value** | Fire event with 0 total | Handled cleanly according to GL rules |

---

## 14. Risks & Mitigation

| Identified Risk | Severity | Mitigation Strategy |
| :--- | :--- | :--- |
| **Missing Expense / Recoverable Tax Accounts in Settings** | **HIGH** | Add required foreign keys to `financial_settings` migration before writing Phase 4.7 listeners. |
| **Duplicate Postings from Legacy Event Listeners** | **MEDIUM** | Deprecate legacy Phase 3 payment listeners (`RecordSalesPaymentListener`, `RecordSupplierPaymentListener`) to prevent double-posting when Phase 4 allocation events fire. |
| **Closed Fiscal Period Event Failures** | **HIGH** | Catch `FiscalPeriodClosedException` in event queue and flag document for finance team review rather than silent drop. |

---

## 15. Missing Decisions & Human Authorization Gate

The following items require human architectural review and ratification before writing Phase 4.7 code:

1. **Default Account Migration Scope:** Should we create a database migration to add `default_expense_account_id`, `default_input_tax_recoverable_account_id`, and `default_sales_returns_account_id` to `financial_settings`?
2. **Legacy Phase 3 Event Listener Deprecation:** Confirm that Phase 3 order-level payment listeners (`RecordSalesPaymentListener` and `RecordSupplierPaymentListener`) should be disabled/replaced by Phase 4 sub-ledger allocation listeners (`PaymentAllocated` and `SupplierPaymentAllocated`).

---

## 16. Recommended Implementation Sequence

Once human authorization is granted:

1. **Step 1:** Create database migration to expand `financial_settings` table columns.
2. **Step 2:** Update `FinancialSettings` model and `AccountResolver` service to resolve new default accounts.
3. **Step 3:** Implement `PostInvoiceToGlListener` listening to `InvoiceIssued`.
4. **Step 4:** Implement `PostCustomerPaymentToGlListener` listening to `PaymentAllocated`.
5. **Step 5:** Implement `PostSupplierInvoiceToGlListener` listening to `SupplierInvoiceApproved`.
6. **Step 6:** Implement `PostSupplierPaymentToGlListener` listening to `SupplierPaymentAllocated`.
7. **Step 7:** Implement `PostCreditNoteToGlListener` listening to `CreditNoteIssued`.
8. **Step 8:** Add comprehensive Phase 4.7 Feature & Integration tests.

---

## 17. Explicit Non-Goals for Phase 4.7

- **DO NOT** modify Phase 4.1–4.6 commercial document models or status state machines.
- **DO NOT** introduce automated GL postings on 3-Way Matching approval (`SupplierInvoiceMatchApproved`).
- **DO NOT** build Phase 5 operational/vertical domain modules (POS, Catering, Transport, Water).

---

## 18. Human Authorization Gate

```
====================================================================================
PHASE 4.7 PRE-IMPLEMENTATION STATUS:
BLOCKED — HUMAN ARCHITECTURAL DECISION REQUIRED
====================================================================================
```

### Ready for Implementation:
- Core GL Engine (`FinancialService`, `Account`, `Journal`, `JournalEntry`, `FiscalPeriod`).
- Event Idempotency System (`ProcessedEvent`).
- Commercial Event Triggers (`InvoiceIssued`, `PaymentAllocated`, `SupplierInvoiceApproved`, `SupplierPaymentAllocated`, `CreditNoteIssued`).

### Missing & Blocking Implementation:
1. `financial_settings` table schema expansion migration for `default_expense_account_id`, `default_input_tax_recoverable_account_id`, and `default_sales_returns_account_id`.
2. Formal sign-off on legacy Phase 3 listener replacement strategy.

---
*Report compiled by Senior Enterprise & Financial Systems Architect.*