Fix remaining correctness issues from Jesper's 2026-09-15 re-review

- dimension-management-wiring: SaveDefaultDim's third argument is the
  shortcut dimension number (1-8), not the field's AL field ID; the
  fixture passed FieldNo(...) = 10. GetDefaultDimID's InheritFromDimSetID
  must be 0 when recomputing after the linking record changes, not the
  document's existing Dimension Set ID (which would retain the previous
  customer's leftover dimensions). Verified against
  DimensionManagement.Codeunit.al and BankDepositHeader.Table.al in the
  BCApps reference clone.
- check-post-line-batch-pattern: "Post Line writes exactly one line to
  the ledger" overclaimed - Gen. Jnl.-Post Line alone calls InsertGLEntry
  from a dozen call sites (balancing entry, VAT, currency rounding,
  deferrals) and can write several G/L Entries per journal line.
  Reworded to "posts exactly one journal line" and softened the
  "distinct, non-overlapping responsibilities" absolute.
- namespace-must-be-verified-from-source.bad.al: dropped the "resolves
  in a local build, fails in VS Code" comment (taught an inherent
  compiler/language-server disagreement that isn't real); reframed as
  stale/cached symbols, matching the prose fix already made.
- file-datatype-saas.good.al: replaced the deprecated 5-argument
  UploadIntoStream overload with the current 2-argument one, and
  actually staged through TempBlob as the article's own Best Practice
  instructs (the declared TempBlob variable was previously unused).
- test-data-must-be-random-and-complete: no longer treats a
  short-but-valid value as defective merely for being "underfilled" -
  AL field lengths are maxima, not minimums. Scoped to missing values
  or a scenario with an explicit length/format requirement (e.g. a
  truncation test). Updated the al-testing-review.md routing cue to
  match.
- stored-derived-fields-must-not-be-exposed-directly: stopped mandating
  source-field exposure as part of the core pattern: the good fixture
  exposed only one of the derived value's two inputs (Hours Used, not
  Budgeted Hours), making the claimed "so the consumer can verify it"
  impossible. Reframed as an optional, all-or-nothing addition and
  fixed the fixture to expose both inputs.

Rebased onto upstream/main to resolve conflicts in
al-breaking-changes-review.md, al-data-modeling-review.md,
al-performance-review.md, and al-style-review.md against merged PRs
#148 and #153; all sides' worklist tokens/cues retained.

microsoft/knowledge/data-modeling/check-post-line-batch-pattern.md

@@ -13,7 +13,7 @@ application-area: [all]
 
 ## Description
 
-Business Central's own journal-based posting routines consistently follow a three-codeunit split with distinct, non-overlapping responsibilities — `Codeunit "Gen. Jnl.-Check Line"` / `"Gen. Jnl.-Post Line"` / `"Gen. Jnl.-Post Batch"` for the general journal, and the same `<Journal>-Check Line` / `<Journal>-Post Line` / `<Journal>-Post Batch` shape repeated for Item, Resource, Job, Fixed Asset, Insurance, and Cost Accounting journals: `Check Line` validates one line, `Post Line` writes exactly one line to the ledger, and `Post Batch` loops both across the journal. A document posting routine (posting one document at a time) calls `Post Line` directly and skips `Post Batch`. This is the standard shape to evaluate a new journal-based posting routine against, not a platform-enforced constraint — a routine with a genuinely different transaction/reuse shape may legitimately organize itself differently. But a new routine that blurs this split without a specific reason either misses functionality other code expects to call directly, or exposes an interaction surface it shouldn't.
+Business Central's own journal-based posting routines consistently follow a three-codeunit split, each with one primary responsibility — `Codeunit "Gen. Jnl.-Check Line"` / `"Gen. Jnl.-Post Line"` / `"Gen. Jnl.-Post Batch"` for the general journal, and the same `<Journal>-Check Line` / `<Journal>-Post Line` / `<Journal>-Post Batch` shape repeated for Item, Resource, Job, Fixed Asset, Insurance, and Cost Accounting journals: `Check Line` validates one line, `Post Line` posts exactly one journal line — `Gen. Jnl.-Post Line` itself can write more than one G/L Entry per call (a balancing entry, VAT, currency rounding, deferrals), so "exactly one line" describes its input, not a one-entry-out guarantee — and `Post Batch` loops both across the journal. A document posting routine (posting one document at a time) calls `Post Line` directly and skips `Post Batch`. This is the standard shape to evaluate a new journal-based posting routine against, not a platform-enforced constraint — a routine with a genuinely different transaction/reuse shape may legitimately organize itself differently, and the three codeunits' responsibilities are a useful default split, not a guarantee that every implementation keeps them non-overlapping. But a new routine that blurs this split without a specific reason either misses functionality other code expects to call directly, or exposes an interaction surface it shouldn't.
 
 ## Best Practice