Regenerate microsoft/knowledge from upstream BCApps instructions

The previous LLM-generated knowledge files contained factual
hallucinations. The most visible was the claim that `FindFirst` /
`FindLast` "forces a full-table scan" on an unfiltered record - it does
not; those APIs return a single row via the current key.

Other inaccuracies the audit found and fixed:

* `FindSet(true)` was described as "taking a LockTable". The correct
  upstream phrasing is that `FindSet(true)` sets
  `ReadIsolation::UpdLock` on the read. UpdLock and LockTable are
  related but distinct mechanisms.
* The list of production-scale tables had been invented beyond the
  upstream source (e.g. "Detailed Cust. Ledg. Entry") without a
  citation. The regenerated list matches the ten tables upstream lists
  with their P95 row counts.
* `SetLoadFields` guidance had been augmented with an extra mechanism
  claim ("the database resolves the filter using the index without
  hydrating the value") not present in upstream.

Approach: full regeneration of `microsoft/knowledge/` from the six
upstream BCApps Code Review instruction files, with Microsoft Learn /
the AL language reference as a secondary source. Every claim in every
regenerated file is anchored to a verbatim upstream quote (or a Learn
URL); the audit trail lives in artifacts/trace-<domain>.json on the
session workspace.

The PR #11 transaction/error-handling cluster is preserved verbatim:

* performance/understand-implicit-transaction-boundary.md
* performance/codeunit-run-as-atomic-sub-operation.{md,good.al,bad.al}
* performance/codeunit-run-requires-prior-commit-inside-transaction.{md,good.al,bad.al}
* performance/use-tryfunction-for-error-catching-not-rollback.{md,good.al,bad.al}
* performance/avoid-commit-inside-loops.{md,good.al,bad.al}
* security/commitbehavior-attribute-scopes-explicit-commits.{md,good.al,bad.al}
* testing/transactionmodel-attribute-governs-test-transactions.{md,good.al,bad.al}

These articles already cite Microsoft Learn and were carefully
cross-referenced; the regeneration skips their topics rather than
duplicating them.

File counts after regeneration:

  performance   35 .md  (5 preserved + 30 new)
  privacy       17 .md
  security      18 .md  (1 preserved + 17 new)
  style         33 .md
  testing        1 .md  (preserved)
  ui            19 .md
  upgrade       18 .md

Total 141 atomic knowledge files, each strictly one rule. All pass
.github/scripts/validate_frontmatter.py with 0 errors and 0 warnings.

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

microsoft/knowledge/upgrade/datatransfer-for-bulk-init.md

@@ -0,0 +1,30 @@
+---
+bc-version: [all]
+domain: upgrade
+keywords: [datatransfer, large-dataset, bulk-update, modifyall, copyfields, new-field]
+technologies: [al]
+countries: [w1]
+application-area: [all]
+---
+
+# Use `DataTransfer` for bulk updates on large tables
+
+## Description
+
+Tables that can contain more than 300,000 records, and any newly added field on an existing table, should be initialized with `DataTransfer` rather than a `repeat ... Modify ... until Next() = 0` loop. `DataTransfer` issues a single set-based statement to the database; the loop/modify pattern issues one round-trip per row and accumulates write locks for the duration of the upgrade. On the volumes that drive upgrade pain — ledger entries, item ledger entries, price list lines — the difference is the upgrade running for minutes instead of hours.
+
+## Best Practice
+
+For a bulk update use a `DataTransfer` variable: call `SetTables(Database::"...", Database::"...")` (source and destination may be the same table), add filters with `AddSourceFilter`, set the target value with `AddConstantValue` (or copy a source field with `AddFieldValue`), and execute with `CopyFields()`. To express multiple distinct updates against the same table, `Clear` the `DataTransfer` between executions and configure the next one.
+
+See sample: `datatransfer-for-bulk-init.good.al`.
+
+## Anti Pattern
+
+Iterating with `FindSet(true) ... repeat ... Modify() ... until Next() = 0` to set a single field across an entire large table. On 300k+ rows this is the canonical slow-upgrade footgun.
+
+See sample: `datatransfer-for-bulk-init.bad.al`.
+
+## See also
+
+- `datatransfer-skips-triggers-and-subscribers.md` — `DataTransfer` does not raise field validation triggers or event subscribers; if a row needs validation logic, `DataTransfer` is the wrong tool.