docs(review): stop rule in the plan loop, review loop and critic prompts (decision 217, 220)

/trekplan Phase 9: when --record or the gate reports the stop rule there
is no new round; AskUserQuestion with the class and counts, "Known issue"
(--accept-open, a security finding refused) or "New mechanism" (stop, the
plan stays unapproved); the round-3 blocker path never offers
--extra-round after the stop rule. Phase 10 prints round of
max_rounds + extra_rounds.

/trekexecute Phase 7.2 step 4: after a round-2 BLOCK or fixed-pending,
before any R-step, review-rounds.mjs prepare --dry-run; review-stop-rule:
gives the same question ("Known issue" = /trekreview --answers, a BLOCKER
keeps the merge locked; "New mechanism" = stop). /trekreview Phase 3 tells
the stop rule's exit 1 from the cap's. plan-critic and scope-guardian:
rule_key names the class, never the instance.

New pins in review-loop-docs, critic-severity-rules and review-prose-pins.

Part 1, step 1.4 of the E plan.

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

tests/lib/review-loop-docs.test.mjs

@@ -138,3 +138,32 @@ test('Handover 4 states the overlap match and the distinct id', () => {
   assert.ok(h4.includes('only on overlapping text'), 'Handover 4 says the gate matches "only on overlapping text"');
   assert.ok(h4.includes('`<rule_key>#n`'), 'Handover 4 names `<rule_key>#n`');
 });
+
+// ---- [STP] the stop rule (E plan, Part 1 step 1.4; decisions 217, 220) ----------------
+
+const P10 = flat(phase(read('commands/trekplan.md'), 10));
+
+/** Phase 9's stop-rule paragraph: from its bold lead to the next bold lead that opens a line. */
+function stopPart() {
+  const at = P9.indexOf('**The stop rule**');
+  assert.ok(at >= 0, 'Phase 9 has a **The stop rule** paragraph');
+  const next = P9.indexOf('**After round 3', at);
+  return P9.slice(at, next < 0 ? undefined : next);
+}
+
+test('[STP] Phase 9: the stop rule gives no new round and asks Known issue or New mechanism, never one more round', () => {
+  const s = stopPart();
+  for (const want of ['stop_rule.fired', 'PLAN_GATE_STOP_RULE', 'no new round', 'AskUserQuestion',
+    '**Known issue**', 'plan-gate.mjs --accept-open', 'PLAN_GATE_SECURITY_OPEN',
+    '**New mechanism**', 'the plan stays unapproved', 'the direction goes to the operator']) {
+    assert.ok(s.includes(want), `the stop-rule paragraph says ${JSON.stringify(want)}`);
+  }
+  assert.doesNotMatch(s, /\*\*One more round\*\*/, 'the stop-rule question has no "One more round" option');
+  assert.ok(P9.includes('never offers `--extra-round` after the stop rule'),
+    'the round-3 blocker path says it never offers --extra-round after the stop rule');
+});
+
+test('[STP] Phase 10 prints the round of max_rounds + extra_rounds', () => {
+  assert.ok(P10.includes('**Critic rounds:** {round} of {max_rounds + extra_rounds}'), 'Phase 10 prints round of max_rounds + extra_rounds');
+  assert.ok(!P10.includes('**Critic rounds:** {N} of {max}'), 'the old "{N} of {max}" is gone');
+});