Address second review round on retention policy knowledge

- Scope both articles to bc-version [22..]: FindOrCreateRetentionPeriod
  first appears in the 21.1 System Application and OnRefreshAllowedTables
  in 22.
- Reframe the default-setup article as optional guidance; registration
  without a setup is valid. The anti-pattern and review routing now cover
  only false claims that registration alone cleans up data.
- Make all four samples self-contained: declare Contoso Activity Log in
  each, add the Retention Policy Setup permission, and guard the default
  setup on IsAllowedTable.
- Let evaluation overrides list additionalArticles and register both
  retention pairs as extra privacy cases (38 cases, existing IDs unchanged).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

microsoft/knowledge/privacy/register-owned-log-tables-for-retention-policies.bad.al

@@ -1,3 +1,19 @@
+table 50567 "Contoso Activity Log"
+{
+    DataClassification = SystemMetadata;
+
+    fields
+    {
+        field(1; "Entry No."; Integer) { AutoIncrement = true; }
+        field(2; "Activity"; Text[250]) { }
+    }
+
+    keys
+    {
+        key(PK; "Entry No.") { Clustered = true; }
+    }
+}
+
 codeunit 50563 "Contoso Activity Log Cleanup"
 {
     Access = Internal;