Promote performance knowledge from community to Microsoft layer

Pure git-mv relocation of all 7 performance articles from community/knowledge/performance/ to microsoft/knowledge/performance/. No content changes.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

microsoft/knowledge/performance/avoid-growing-globals-in-singleinstance-subscribers.good.al

@@ -0,0 +1,28 @@
+codeunit 50100 "Event Audit Buffer"
+{
+    SingleInstance = true;
+
+    var
+        RecentEventIds: List of [Guid];
+        MaxBuffered: Integer;
+
+    trigger OnRun()
+    begin
+        MaxBuffered := 50;
+    end;
+
+    [EventSubscriber(ObjectType::Table, Database::"Sales Header", OnAfterInsertEvent, '', false, false)]
+    local procedure OnAfterInsertSalesHeader(var Rec: Record "Sales Header")
+    begin
+        // Bounded cache: drop the oldest entry when the cap is reached.
+        RecentEventIds.Add(Rec.SystemId);
+        if RecentEventIds.Count() > MaxBuffered then
+            RecentEventIds.RemoveAt(1);
+    end;
+
+    procedure ResetAtBusinessProcessBoundary()
+    begin
+        // Explicit reset point at a natural boundary in the workflow.
+        Clear(RecentEventIds);
+    end;
+}