fix: round 5 of the release review of 6.3.0, the structural fix

Round 5 (v6.2.0..d37e538, WARN: 11 MAJOR, 2 MINOR). The patching did not
converge (the same two places every round), so the operator chose a
structural fix on 2026-10-11. Each change behind a test that failed first.

- A check runs with no shell. criteria-runner's runCommand starts the runner
  with the very words the screen checked (spawnSync(words[0], words.slice(1)),
  without NODE_TEST_CONTEXT); Phase 7 criteria, Regression: (its exec copy is
  gone, MINOR 0e98d5c7), proof of red, the done line and the test lock all
  run through it. No quote, glob, tilde or variable can rewrite a checked
  word any more. The screen stays and says why: a word that means something
  else in a shell (quote, backslash, $, brace, leading ~) is refused; a glob
  reaches only node --test, which expands its own patterns (sh read
  `tests/.?/` as `tests/../`); no path climbs out with .. or starts at /;
  a word starting with @ is refused (pytest reads @file as more arguments).
- The K6 plan-file sweep has v6.2.0's own Files: reader again (516dffa):
  backticked paths, and plain words only in a field without them. The
  shared reader from round 3 planned directories a description named and
  dropped paths v6.2.0 planned. fieldPaths stays for the tests-only check,
  with a path test on spans (`parse()`, `p.parse()` are no paths), plain
  descriptions ignored when the field has backticked paths, dotfiles,
  backslash paths and glued spans read.
- Skill frontmatter reads a value as YAML does: trailing space is nothing,
  and a comment ends a plain value, a flow list or a block indicator
  (`model: opus # pinned`). A comment that cuts a plain description, or is
  the whole value, is still a hazard.
- release-check reads the diff with --no-renames: a test moved into an
  allowed place after the review shows as removed.
- The example plan's step 2 heading no longer says "must FAIL initially";
  steps 1-2 keep the tests-only warning (operator 2026-10-09, 73262b6).

Open: MINOR c1fef1ad (one shared isMain helper) is not in this round.
Measured: 0 of 463 Files: fields with backticked paths (520 fields in 182
plans across the marketplace repos) carry another path-like word.

Suite 2185 (2183/0/2).

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

examples/01-add-verbose-flag/plan.md

@@ -85,7 +85,7 @@ or stability harness comes before behavior change.
     must_contain: []
   ```
 
-### Step 2: Add stability test (must FAIL initially — verbose not yet wired)
+### Step 2: Add stability test (passes today — the canary for step 5 onwards)
 
 - **Files:** `tests/cli-no-verbose-stability.test.mjs` (new file)
 - **Changes:** Three subtests, one per golden file. Each runs `node src/cli.mjs <cmd> ...` and asserts stdout `===` `readFileSync('tests/golden/<cmd>.stdout')`. The test should PASS today (no behavior change yet) — it's the canary for step 5 onwards.

examples/01-add-verbose-flag/progress.json

@@ -28,7 +28,7 @@
     },
     {
       "n": 2,
-      "title": "Add stability test (must FAIL initially — verbose not yet wired)",
+      "title": "Add stability test (passes today — the canary for step 5 onwards)",
       "status": "completed",
       "started_at": "2026-05-01T10:16:01Z",
       "completed_at": "2026-05-01T10:18:42Z",