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/entry-application.md

@@ -0,0 +1,30 @@
+---
+bc-version: [1..99]
+domain: finance
+keywords: [entry-application, remaining-amount, payment-discount, payment-tolerance, codeunit-226, codeunit-227]
+technologies: [al]
+countries: [w1]
+application-area: [finance]
+---
+
+# Entry application
+
+## Description
+
+Entry application is the mechanism by which payments close invoices, credit memos offset invoices, and refunds close credits. A customer ledger entry carries a Remaining Amount that tracks the unapplied balance; an application event (Apply Customer Entries / Apply Vendor Entries) reduces Remaining Amount on both sides of the application until one side hits zero. Codeunit 226 (`CustEntry-Apply Posted Entries`) handles customer applications; codeunit 227 (`VendEntry-Apply Posted Entries`) handles vendors. Both route through codeunit 12 for the G/L posting and write Detailed Cust./Vendor Ledger Entries that preserve the application history.
+
+Two tolerances add flexibility. Payment Discount gives a counterparty a reduced amount if they pay within a grace window; when the payment matches the discounted amount, the invoice closes and a discount-expense G/L Entry records the difference. Payment Tolerance lets a slightly short payment still close an invoice; the shortfall posts to a Payment Tolerance account. Both are configured on the Sales & Receivables Setup and Vendor Posting Groups; both can be disabled per customer/vendor.
+
+Applications across currencies trigger an exchange-rate adjustment inside the application itself: the FCY amounts apply directly, but the LCY equivalent of each leg may differ because the rates at posting dates differ. The difference posts to an exchange gain/loss account as part of the application, independent of the period-end Adjust Exchange Rates batch.
+
+## Best Practice
+
+Let the Apply action compute the amounts. Manually setting Amount to Apply on one side and letting the other auto-calculate produces rounding that can leave tiny (0.01) Remaining Amounts that block closing the period.
+
+## Anti Pattern
+
+Scripting direct updates to Remaining Amount to close out a balance. The Detailed Cust./Vendor Ledger Entry chain no longer matches and the entry, while appearing closed, cannot be un-applied or reversed cleanly.
+
+## Provenance
+
+Migrated from microsoft/BCAppsTriage's `plugins/triage/skills/triage/references/area-knowledge/finance.md` (section: "Entry Application") on 2026-04-21.