fix(verification): a section the runner cannot read SAYS so, and trekplan is pinned to the format it reads

Measured 2026-09-18: nine ordinary shapes of a plan's `## Verification`
section parsed to zero criteria - an untagged fence, a ```text fence, a
markdown table, `## Verification (acceptance)`, `## Verification:`,
`### Verification`, an unclosed fence earlier in the document. Every one came
out as `0 of 0`, NOT OK, exit 1, and Phase 7 then forbade `result: completed`
without anyone being told that the FORMAT, not the code, was the problem.
"The section is empty" and "I cannot read this format" are different facts.

Three changes, one hole:

- The runner reports `NO_CRITERIA` with a source line (`plan.md:NN`) when the
  section is there and nothing in it parsed, and names the two forms it does
  read. Same for a brief's `## Success Criteria`, so the evidence block the
  conformance reviewer gets says which of the two it is looking at rather than
  showing an empty table.
- Phase 7 says it out loud instead of failing silently: report the source line
  and the two forms, and say that the plan is what failed there, not the run.
- `/trekplan` now pins what it produces to what the runner reads: the heading
  is exactly `## Verification`, the criteria are a bullet whose first
  backticked span is the command or a shell-tagged fence, and the command must
  be one the allowlist runs. A doc-consistency test holds the writer and the
  reader together, so a runner that learns a new form must update the source.

Honest about the round trip: the two round-trip tests were GREEN on arrival -
the template already writes the bullet form the runner reads. What was missing
was not the format but the PIN: `/trekplan` mandated neither the heading string
nor the format, so a plan could satisfy the command's own instructions and
still parse to nothing. The tests now hold that.

Red first: 5 of the 7 new tests failed before the change (3 NO_CRITERIA, 2
doc-consistency); the 2 round-trip tests are guards, and said so above.
Suite 1161 (1159/0/2). Gate unchanged: defects 0 of 7, intact, exit 1.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

lib/verification/criteria-runner.mjs

@@ -83,8 +83,10 @@ function scanLines(markdown) {
   return out;
 }
 
-// The lines from `heading` up to the next `## ` heading (exclusive). Headings
-// inside a fence do not count on either end.
+// The lines from `heading` up to the next `## ` heading (exclusive), plus the
+// 1-based line the heading itself is on — a section the runner cannot read has
+// to be reported with a place to look. Headings inside a fence do not count on
+// either end.
 function sectionLines(markdown, heading) {
   const lines = scanLines(markdown);
   const start = lines.findIndex((l) => !l.fenced && l.text.trim() === heading);
@@ -93,7 +95,7 @@ function sectionLines(markdown, heading) {
   for (let i = start + 1; i < lines.length; i++) {
     if (!lines[i].fenced && lines[i].text.startsWith('## ')) { end = i; break; }
   }
-  return lines.slice(start + 1, end);
+  return { line: start + 1, lines: lines.slice(start + 1, end) };
 }
 
 // `- [ ] text`, `- [x] text`, `- text`, `* text`, `1. text` -> text
@@ -154,8 +156,9 @@ function fencedCommand(text) {
 }
 
 function parseSection(markdown, heading, prefix) {
-  const lines = sectionLines(markdown, heading);
-  if (lines === null) return [];
+  const section = sectionLines(markdown, heading);
+  if (section === null) return [];
+  const lines = section.lines;
   const criteria = [];
   const push = (text, command, reason) =>
     criteria.push({ label: `${prefix}${criteria.length + 1}`, text, command, reason });
@@ -408,6 +411,27 @@ function report(kind, source, criteria, opts, error) {
   };
 }
 
+/**
+ * The section is THERE and nothing in it parsed as a check.
+ *
+ * "The section is empty" and "I cannot read this format" are different facts,
+ * and reporting both as `0 of 0` collapsed them into one bare exit 1. Measured
+ * 2026-09-18: nine ordinary shapes of a `## Verification` section — an untagged
+ * fence, a ```text fence, a table, a heading with a suffix, an unclosed fence
+ * earlier in the file — all came out that way, and the run was felled without
+ * anyone being told which format the runner had failed to read.
+ */
+function noCriteria(source, heading, line) {
+  return {
+    code: 'NO_CRITERIA',
+    message:
+      `${source}:${line} — the "${heading}" section declares nothing the runner can read. `
+      + 'It reads two forms: a bullet whose first backticked span is the command '
+      + '(`- [ ] `npm test` -> expected: exit 0`), and a shell-tagged fence (```bash) '
+      + 'whose lines are the commands. An untagged fence, a table or prose parses to nothing.',
+  };
+}
+
 function readOrThrow(path) {
   try {
     return readFileSync(path, 'utf8');
@@ -425,13 +449,18 @@ function readOrThrow(path) {
  */
 export function runPlanVerification(planPath, opts = {}) {
   const md = readOrThrow(planPath);
-  if (sectionLines(md, PLAN_HEADING) === null) {
+  const section = sectionLines(md, PLAN_HEADING);
+  if (section === null) {
     return report('plan', planPath, [], opts, {
       code: 'NO_VERIFICATION_SECTION',
       message: `${planPath} has no "${PLAN_HEADING}" section — nothing to verify, so the run cannot be called verified`,
     });
   }
-  return report('plan', planPath, parsePlanVerification(md), opts);
+  const criteria = parsePlanVerification(md);
+  if (criteria.length === 0) {
+    return report('plan', planPath, [], opts, noCriteria(planPath, PLAN_HEADING, section.line));
+  }
+  return report('plan', planPath, criteria, opts);
 }
 
 /**
@@ -440,13 +469,18 @@ export function runPlanVerification(planPath, opts = {}) {
  */
 export function runSuccessCriteriaChecks(briefPath, opts = {}) {
   const md = readOrThrow(briefPath);
-  if (sectionLines(md, BRIEF_HEADING) === null) {
+  const section = sectionLines(md, BRIEF_HEADING);
+  if (section === null) {
     return report('brief', briefPath, [], opts, {
       code: 'NO_SUCCESS_CRITERIA_SECTION',
       message: `${briefPath} has no "${BRIEF_HEADING}" section`,
     });
   }
-  return report('brief', briefPath, parseSuccessCriteria(md), opts);
+  const criteria = parseSuccessCriteria(md);
+  if (criteria.length === 0) {
+    return report('brief', briefPath, [], opts, noCriteria(briefPath, BRIEF_HEADING, section.line));
+  }
+  return report('brief', briefPath, criteria, opts);
 }
 
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