Add 15 community knowledge articles from BC Code Intel ingest

Ingests net-new /community knowledge from BC Code Intelligence, surviving
the admission test, gray-zone salvage, and dedup against the full corpus.

Domains: ui (6), error-handling (3), performance (2), upgrade (1),
appsource (1), security (1), telemetry (1). The two BC24 No. Series
migration drafts are merged into one article.

Adds good/bad AL samples for the clean-fit articles (error-handling,
performance, security, telemetry). UI and appsource remain knowledge-only.

Validator and knowledge-index checks pass (207 articles).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

community/knowledge/error-handling/fielderror-vs-testfield.bad.al

@@ -0,0 +1,26 @@
+table 50122 "FieldError vs TestField Bad"
+{
+    fields
+    {
+        field(1; "No."; Code[20]) { }
+        field(2; "Posting Date"; Date) { }
+        field(3; "Amount"; Decimal) { }
+    }
+
+    procedure PostDocument()
+    begin
+        // FieldError performs no comparison and always raises the moment it is
+        // reached, so this "check" terminates PostDocument every time — the
+        // Posting Date is never actually tested, and the amount rule below is
+        // dead code.
+        FieldError("Posting Date", 'must be filled in');
+
+        if IsAmountOutsideAllowedRange("Amount") then
+            Error('Amount is out of range.');
+    end;
+
+    local procedure IsAmountOutsideAllowedRange(Value: Decimal): Boolean
+    begin
+        exit((Value < 0) or (Value > 1000000));
+    end;
+}