Add unit tests and knowledge files for BC domain context

- Introduced unit tests for the bc-domain-context implementation, covering various scenarios including filtering by application area, technology mismatches, layer precedence, and conditional applicability.
- Added knowledge files related to finance, including topics such as Chart of Accounts, Codeunit 12, Dimension Management, and VAT on prepayment chains, among others.
- Each knowledge file includes structured metadata and best practices to enhance the domain knowledge available for Business Central tasks.

microsoft/knowledge/finance/multi-currency-rounding.md

@@ -0,0 +1,28 @@
+---
+bc-version: [1..99]
+domain: finance
+keywords: [multi-currency, rounding, currency-precision, invoice-rounding, fcy-lcy]
+technologies: [al]
+countries: [w1]
+application-area: [finance]
+---
+
+# Multi-currency rounding
+
+## Description
+
+Every Currency record (table 4) declares four rounding precisions that govern how BC handles foreign-currency (FCY) amounts: Amount Rounding Precision (typically 0.01), Unit-Amount Rounding Precision (typically 0.00001, used for unit prices), Invoice Rounding Precision (typically 0.01, the tolerance that lets an invoice round to a "clean" final amount), and Appln. Rounding Precision (tolerance for closing applications across currencies). The four precisions interact with the local currency's precision to determine what amounts a document ends up posting.
+
+At post time the codeunit computes three amounts per line: the FCY amount (rounded to Amount Rounding Precision), the LCY amount (FCY × exchange rate, rounded to the local currency's precision), and any residual that falls to the Invoice Rounding account configured on the Customer/Vendor Posting Group. Rounding conflicts appear when: (a) LCY precision is coarser than FCY — JPY bookkeeping with EUR documents rounds to whole yen but allows 0.01 EUR; (b) per-line rounding on a many-line document diverges from single-line rounding of the document total; (c) the exchange rate changes between an order's receipt and its invoice, and the rounding residual shifts.
+
+## Best Practice
+
+Use the Invoice Rounding account purposefully — set it to a dedicated G/L account so the residuals aggregate where finance can review them. A catch-all "other income" lumps them with real transactions and hides rounding drift.
+
+## Anti Pattern
+
+Disabling Invoice Rounding by setting the precision to 0. The residuals then split across every VAT and payment account, making period-end reconciliation a hunt for pennies that do not belong to any transaction.
+
+## Provenance
+
+Migrated from microsoft/BCAppsTriage's `plugins/triage/skills/triage/references/area-knowledge/finance.md` (section: "Multi-Currency — Rounding and Exchange Rates") on 2026-04-21.