Seed community performance and security knowledge

Ports 14 concern-sized articles (8 performance, 6 security) and 25
AL samples from BC Code Intelligence, restructured to BCQuality's v1
schema and layered under /community/knowledge/. Each article is
atomic, under 100 lines, and ships <slug>.good.al and (where the
pattern has a clear anti-example) <slug>.bad.al siblings.

Jesper's microsoft-layer leaves (al-performance-review and
al-security-review) source across every enabled layer via
*/knowledge/<domain>/**, so these additions are picked up by the
existing action skills without any new skill definitions.

Performance (8):
  - use-deleteall-for-filtered-bulk-deletion
  - call-setloadfields-before-filters
  - load-common-fields-before-branching-on-case
  - load-only-primary-key-fields-for-reference-work
  - omit-filter-only-fields-from-setloadfields
  - choose-maintainsiftindex-by-read-write-ratio
  - avoid-growing-globals-in-singleinstance-subscribers
  - order-case-branches-by-frequency

Security (6):
  - classify-every-field-with-dataclassification
  - protect-sensitive-data-in-temporary-tables
  - guard-bulk-operations-with-istemporary
  - compose-permission-sets-with-included-sets
  - do-not-grant-rights-beyond-a-users-entitlement
  - prefer-oauth2-over-api-keys-for-external-http-calls

Graveyard-bound items (not ported; to be captured in a later
/docs/triage-graveyard.md):
  - testfield-performance (soft guidance, low actionability)
  - table-event-batch-operation-impact (keep-event-subscribers-lightweight
    already carries the core insight)
  - Most of /roger-reviewer (AL formatting - frontier-model territory)
  - sift-technology-fundamentals (descriptive, not a citable concern)
  - bc-telemetry-buddy-* (tooling promotion, not guidance)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

community/knowledge/security/classify-every-field-with-dataclassification.good.al

@@ -0,0 +1,36 @@
+table 50100 "Customer Feedback"
+{
+    fields
+    {
+        field(1; "Feedback No."; Code[20])
+        {
+            DataClassification = SystemMetadata;
+        }
+        field(2; "Contact Name"; Text[100])
+        {
+            DataClassification = EndUserIdentifiableInformation;
+        }
+        field(3; "Email"; Text[80])
+        {
+            DataClassification = EndUserIdentifiableInformation;
+        }
+        field(4; "Product Code"; Code[20])
+        {
+            DataClassification = CustomerContent;
+        }
+        field(5; "Feedback Text"; Text[2048])
+        {
+            // When uncertain between CustomerContent and EUII, prefer the stronger protection.
+            DataClassification = EndUserIdentifiableInformation;
+        }
+        field(6; "Submitted DateTime"; DateTime)
+        {
+            DataClassification = SystemMetadata;
+        }
+    }
+
+    keys
+    {
+        key(PK; "Feedback No.") { Clustered = true; }
+    }
+}