feat(plan): the operative line map and a deterministic line diff for the critic loop [skip-docs]

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/validators/plan-gate.mjs

@@ -100,6 +100,47 @@ export function operativeText(text) {
     .trim() + '\n';
 }
 
+/**
+ * The operative text with its line map, built from the same transforms as
+ * `operativeText` (whose output it returns unchanged).
+ * @returns {{text: string, fullToOp: Array<number|null>, opToFull: Array<number|null>}}
+ *   1-based both ways (index 0 is null). fullToOp[i] is null for a review-log
+ *   line, the quality line or a collapsed blank; opToFull[j] is null for an
+ *   operative line no file line carries (a blank left where a log section stood).
+ */
+export function operativeLines(text) {
+  const src = norm(text);
+  const full = src.split('\n');
+  const excluded = new Set();
+  for (const s of splitSections(src, 2)) {
+    if (!isLogTitle(s.title)) continue;
+    const n = logPart(s.text).log.split('\n').length;
+    for (let i = s.start; i < s.start + n; i++) excluded.add(i);
+  }
+  full.forEach((l, i) => { if (QUALITY_LINE.test(l)) excluded.add(i); });
+  const op = operativeText(text);
+  const opL = op.split('\n');
+  const opCount = opL.length - 1; // the text ends with '\n'; the last split element is not a line
+  const fullToOp = new Array(full.length + 1).fill(null);
+  const opToFull = new Array(opCount + 1).fill(null);
+  let j = 0;
+  for (let i = 0; i < full.length && j < opCount; i++) {
+    if (excluded.has(i)) continue;
+    let l = full[i].replace(/[ \t]+$/, '');
+    if (j === 0) l = l.replace(/^\s+/, '');
+    // Only blanks lose their partner, so a non-blank kept line facing an operative
+    // blank means that blank has no file line: step past it.
+    while (l !== '' && opL[j] === '' && j < opCount - 1) j += 1;
+    const want = opL[j];
+    if (l === want || (j === opCount - 1 && l.trimEnd() === want)) {
+      fullToOp[i + 1] = j + 1;
+      opToFull[j + 1] = i + 1;
+      j += 1;
+    }
+  }
+  return { text: op, fullToOp, opToFull };
+}
+
 export function planHash(text) {
   return createHash('sha256').update(operativeText(text)).digest('hex');
 }