Add data-modeling and appsource knowledge articles (MICROSOFT layer) (#65)

Author 7 remedial BCQuality knowledge articles plus good/bad AL samples
(21 files) covering AL master-table and data-model design:

- data-modeling: master No. from number series in OnInsert; use codeunit
  "No. Series" not obsolete NoSeriesManagement; setup table is a singleton;
  set Last Date Modified in OnModify and OnRename; enforce Blocked in
  referencing code not in the master.
- style: ApplicationArea required on page controls (AS0062).
- appsource: object affixes prevent collisions (AS0011).

Clean-room authored from own BC knowledge; specifics verified against public
sources only (learn.microsoft.com, microsoft/BCApps). Introduces two new
domains (data-modeling, appsource).

Co-authored-by: Jesper Schulz-Wedde <jesper.schulzwedde@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

microsoft/knowledge/appsource/object-affixes-prevent-collisions.good.al

@@ -0,0 +1,40 @@
+// Own object: the affix "ABC" is carried at object-name level.
+table 50377 "ABC Loyalty Tier"
+{
+    Caption = 'Loyalty Tier';
+    DataClassification = CustomerContent;
+
+    fields
+    {
+        field(1; "Code"; Code[20])
+        {
+            Caption = 'Code';
+        }
+        field(10; Description; Text[100])
+        {
+            Caption = 'Description';
+        }
+    }
+
+    keys
+    {
+        key(PK; "Code")
+        {
+            Clustered = true;
+        }
+    }
+}
+
+// Extension of a standard object: the added field is individually affixed,
+// because the object name (Customer) belongs to the base application.
+tableextension 50376 "ABC Customer Ext" extends Customer
+{
+    fields
+    {
+        field(50376; "Loyalty Points ABC"; Integer)
+        {
+            Caption = 'Loyalty Points';
+            DataClassification = CustomerContent;
+        }
+    }
+}