Add new action skills for AL testing and documentation

- Introduced `al-test-writer` to generate AL test codeunits for production objects based on TDD principles.
- Added `al-userguide-test-writer` to create test codeunits from user guide steps, mapping actions and assertions.
- Implemented `bc-extension-test-guide` to generate a comprehensive TEST_GUIDE.md for Business Central extensions, covering various categories.
- Created `bc-webclient-runner` to automate UI testing of the Business Central web client, capturing screenshots and asserting UI states.
- Developed `page-scripting-e2e` to produce a recording plan for Page Scripting, ensuring a structured approach to browser-level testing.

custom/knowledge/integration/propagate-a-correlation-id-across-every-hop.good.al

@@ -0,0 +1,54 @@
+// Best practice: mint the correlation id ONCE at the entry point and carry it unchanged on
+// every staged message, event payload, queue header, and outbound call. Log it at every step,
+// so one filter pulls the entire flow across BC, the queue, and the external system.
+
+codeunit 50190 "Inbound Entry"
+{
+    // The boundary: this is the ONLY place a correlation value is created. Everything downstream
+    // reads it, never regenerates it.
+    procedure Receive(Payload: Text)
+    var
+        IntegrationMessage: Record "Integration Message";
+    begin
+        IntegrationMessage.Init();
+        IntegrationMessage."Message ID" := CreateGuid();
+        // Generated once, here, at the entry point. This is the trace id for the whole flow.
+        IntegrationMessage."Correlation ID" := NewCorrelationId();
+        IntegrationMessage.SetRequest(Payload);
+        IntegrationMessage.Insert(true);
+
+        // Log it on the very first step, so even the inbound receipt is part of the trace.
+        LogStep('received', IntegrationMessage."Correlation ID");
+    end;
+
+    local procedure NewCorrelationId(): Code[40]
+    begin
+        exit(CopyStr(DelChr(LowerCase(Format(CreateGuid())), '=', '{}'), 1, 40));
+    end;
+}
+
+codeunit 50191 "Outbound Step"
+{
+    // A downstream hop. It READS the correlation id off the message it was handed; it does not
+    // mint a new one, because that would split the flow into two untraceable halves.
+    procedure Send(var IntegrationMessage: Record "Integration Message")
+    var
+        Client: HttpClient;
+        Request: HttpRequestMessage;
+        Headers: HttpHeaders;
+        Response: HttpResponseMessage;
+    begin
+        Request.SetRequestUri('https://svc.contoso.com/api/orders');
+        Request.Method := 'POST';
+        Request.GetHeaders(Headers);
+
+        // Carry the SAME id onto the outbound call as a header. The receiver logs it too, so the
+        // external system's logs can be joined back to the BC side by this one value.
+        Headers.Add('Correlation-Id', IntegrationMessage."Correlation ID");
+
+        Client.Send(Request, Response);
+        // Same id logged on this hop. Request and confirmation rows share it, so a status query
+        // or failure investigation pulls the whole chain with a single filter.
+        LogStep('sent', IntegrationMessage."Correlation ID");
+    end;
+}