[TASK] Implement invoice balance updates after credit note test - Credit Note and Refund Workflow

[africanitem]

Task Details

Epic: #551 [EPIC] Credit Note and Refund Workflow E2E Tests

Dependencies

• Depends on: [TASK] Implement credit note application to invoice test - Credit Note and Refund Workflow #555

Success Criteria

• Test verifies invoice balance updates after credit note, verifies balance is calculated correctly