Seed security knowledge corpus (16 articles + 30 AL samples)

Converts Jesper's existing AL security-review prompt into BCQuality seed
knowledge articles so the al-security-review leaf has a real corpus to
match against. Mirrors the performance seed phase.

Articles under microsoft/knowledge/security/ (16):
- Permission model: follow-least-privilege-in-permission-sets,
  use-indirect-permissions-for-elevated-access,
  use-inherent-permissions-to-grant-minimal-access
- Secrets: never-hardcode-secrets-in-al,
  use-isolated-storage-for-module-and-company-secrets,
  prefer-azure-key-vault-for-production-secrets,
  use-secrettext-for-credentials, use-secrettext-with-httpclient,
  compose-secrets-with-secretstrsubstno,
  use-nondebuggable-when-parsing-secrets
- External calls: require-https-for-external-calls,
  set-timeouts-for-external-calls, do-not-put-credentials-in-urls
- Error handling: avoid-sensitive-data-in-error-messages,
  do-not-swallow-security-errors-silently
- Extensibility: do-not-expose-sensitive-data-in-event-publishers

Paired AL samples under samples/security/<slug>/{bad,good}.al, object
IDs 50200-50231 (no overlap with performance 50100-50140).

Rubber-duck findings addressed:
- HttpClient secret-URI: SetSecretRequestUri is on HttpRequestMessage
  (not HttpClient). Rewrote use-secrettext-with-httpclient and its
  good sample to use HttpRequestMessage + HttpClient.Send.
- InherentPermissions only grants access to same-extension objects;
  the sample now defines its own table 50230 "Sec Sample Lookup" and
  grants 'r' on that, not on Database::Customer.
- Reworked compose-secrets-with-secretstrsubstno bad.al away from
  Format(SecretText) (unreliable) to a plain Text+StrSubstNo anti-
  pattern.
- Moved normative guidance out of Description in three articles
  (compose-secrets-..., prefer-azure-key-vault-..., use-inherent-...)
  so it sits in Best Practice / Anti Pattern per READ contract.
- Added a companion helper codeunit (50231) to the indirect-permissions
  good sample so it actually demonstrates the controlled write path.
- Rebuilt the event-publisher good/bad pair on the same ExportCustomer
  scenario so the contrast is the shape of the event signature, not a
  different event.

Also: broaden samples/README.md object-ID range note to 50100-50299.

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

samples/README.md

@@ -18,7 +18,7 @@ Some articles only have a `good.al` (best practice only) or only a `bad.al` (pur
 
 ## Status
 
-All samples are **demonstration-only**. They are self-contained AL objects with object IDs in the 50100-50199 range and are not meant to be deployed, nor are they derived from Microsoft's Business Central base application source. They exist to make the accompanying knowledge articles concrete for human readers and for agents that benefit from a worked example.
+All samples are **demonstration-only**. They are self-contained AL objects with object IDs in the 50100-50299 range and are not meant to be deployed, nor are they derived from Microsoft's Business Central base application source. They exist to make the accompanying knowledge articles concrete for human readers and for agents that benefit from a worked example.
 
 ## Referencing samples from knowledge articles