feat(ms-ai-architect): R20 — Category-backfill på 25 kategorisløse ref-filer via insertMetaField [skip-docs]

Ny testet primitiv transform.insertMetaField (anker + 500B-back-off som insertHeaderFields, idempotent på eksakt label, body byte-identisk; 6 tester) + backfill-category.mjs (deterministisk folder->category-regel, hard per-fil-invariant, insert-only, aborterer for skriving ved avvik).

Fordeling: 14 Solution Architecture & Advisory (architecture/), 6 Microsoft AI Platforms (platforms/+development/), 4 Responsible AI & Governance, 1 MLOps & GenAIOps. Label = engelsk Category (322 vs 42 Kategori). Eksisterende recommended-mcp-servers/rag-maturity-model urort.

Roadmap: R20 done + R21 (Status/Last-updated not-due) encoded. Verifisering: 0 kategorislose filer (var 25); diff +25/-0; idempotent re-run; suite 764/764 exit 0.

scripts/kb-update/lib/transform.mjs

@@ -359,6 +359,65 @@ export function insertHeaderFields(content, meta) {
   return lines.join('\n');
 }
 
+/**
+ * Surgically insert ONE bold-label meta line — `**<label>:** <value>` — into an EXISTING KB
+ * file that lacks it: the R20/R21 base-field backfill primitive (**Category:** in R20;
+ * **Status:** / **Last updated:** in R21). Reuses insertHeaderFields' anchor + 500-byte
+ * back-off discipline — the line lands immediately after the last line of the first
+ * contiguous bold-label meta run that still leaves room in the window, with a title fallback
+ * for the "None" dialect (no meta lines). Idempotent on the EXACT label: a file already
+ * carrying `**<label>:**` anywhere in the header region is returned unchanged. The body (from
+ * the first `## ` section) is byte-identical.
+ *
+ * Unlike insertHeaderFields (Port-1 Type/Source, with type validation) this is field-agnostic
+ * — it keys on the label shape only, so it never re-derives a value or touches other lines.
+ *
+ * @param {string} content — full existing file content
+ * @param {string} label — the bold label WITHOUT the `**`/`:` decoration, e.g. 'Category'
+ * @param {string} value — the field value
+ * @returns {string} content with the meta line inserted, or unchanged if the label is present
+ * @throws if label or value is blank
+ */
+export function insertMetaField(content, label, value) {
+  const s = String(content ?? '');
+  const lab = String(label ?? '').trim();
+  const val = String(value ?? '').trim();
+  if (lab === '') throw new Error('insertMetaField: label is required');
+  if (val === '') throw new Error('insertMetaField: value is required');
+
+  const lines = s.split('\n');
+  const esc = lab.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+  const labelRe = new RegExp('^\\s*\\*\\*' + esc + ':\\*\\*', 'i');
+
+  // Idempotent: if the exact label already appears in the header region, return unchanged.
+  for (const line of lines) {
+    if (/^##\s/.test(line) || /^---\s*$/.test(line)) break; // reached body / rule
+    if (labelRe.test(line)) return s;
+  }
+
+  // Anchor: last line of the first contiguous meta run whose insertion point still fits the
+  // 500-byte window; title fallback for the "None" dialect (mirrors insertHeaderFields).
+  let anchorIdx = -1;
+  let titleIdx = -1;
+  let cum = 0;
+  for (let i = 0; i < lines.length; i++) {
+    const line = lines[i];
+    if (/^##\s/.test(line) || /^---\s*$/.test(line)) break; // reached body / rule
+    if (titleIdx === -1 && /^#\s+\S/.test(line)) titleIdx = i;
+    const nextCum = cum + line.length + 1; // byte offset just AFTER this line
+    if (RE_META_LINE.test(line)) {
+      if (nextCum > HEADER_REGION_BYTES) break; // back off — insertion point past the window
+      anchorIdx = i;
+    } else if (anchorIdx !== -1) {
+      break; // first non-meta line after the run — the contiguous run is over
+    }
+    cum = nextCum;
+  }
+  const at = (anchorIdx !== -1 ? anchorIdx : titleIdx) + 1; // -1 + 1 = 0 → very top if no title
+  lines.splice(at, 0, `**${lab}:** ${val}`);
+  return lines.join('\n');
+}
+
 /**
  * Surgically insert-or-update ONLY the `**Verified:**` and `**Verified by:**` header lines
  * on an EXISTING KB file — the R7–R10 born-verified STAMP primitive. Unlike composeKbFile