fix(review-army): keep the state-machine detector's output only on exit 0 (W3-5 confirm round)

A failing gstack-state-matrix detect prints SCOPE_STATE_MACHINE=false before
exiting non-zero. The scope block now captures its output and sources it only
when the detector succeeds; otherwise it discards the output, sets
SCOPE_STATE_MACHINE=unknown (dispatching the State Machines specialist) and
leaves the detector's stderr visible. Free tests cover false-output/non-zero,
empty-output/non-zero and a late failure after printing true. The stack
comment is shortened so gstack-review stays 4 chars under its pin; the five
host pins are lowered to match.

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

test/fixtures/skill-md-size-allowlist.json

@@ -37,7 +37,7 @@
     "cursor/gstack-plan-design-review": 138935,
     "cursor/gstack-plan-devex-review": 134558,
     "cursor/gstack-plan-eng-review": 151523,
-    "cursor/gstack-review": 141047,
+    "cursor/gstack-review": 141043,
     "factory/gstack-autoplan": 131397,
     "factory/gstack-codex": 100523,
     "factory/gstack-design-consultation": 108523,
@@ -47,7 +47,7 @@
     "factory/gstack-plan-design-review": 141716,
     "factory/gstack-plan-devex-review": 137927,
     "factory/gstack-plan-eng-review": 154637,
-    "factory/gstack-review": 144829,
+    "factory/gstack-review": 144825,
     "gbrain/gstack-autoplan": 129650,
     "gbrain/gstack-design-review": 132733,
     "gbrain/gstack-land-and-deploy": 116039,
@@ -67,7 +67,7 @@
     "kiro/gstack-plan-design-review": 138775,
     "kiro/gstack-plan-devex-review": 134398,
     "kiro/gstack-plan-eng-review": 151373,
-    "kiro/gstack-review": 140853,
+    "kiro/gstack-review": 140849,
     "openclaw/gstack-autoplan": 129355,
     "openclaw/gstack-design-review": 131538,
     "openclaw/gstack-land-and-deploy": 115627,
@@ -82,7 +82,7 @@
     "opencode/gstack-plan-design-review": 140705,
     "opencode/gstack-plan-devex-review": 136779,
     "opencode/gstack-plan-eng-review": 153275,
-    "opencode/gstack-review": 143295,
+    "opencode/gstack-review": 143291,
     "slate/gstack-autoplan": 128994,
     "slate/gstack-design-consultation": 106996,
     "slate/gstack-design-review": 142272,
@@ -90,6 +90,6 @@
     "slate/gstack-plan-design-review": 138855,
     "slate/gstack-plan-devex-review": 134478,
     "slate/gstack-plan-eng-review": 151448,
-    "slate/gstack-review": 140950
+    "slate/gstack-review": 140946
   }
 }

test/review-workflow-clarity.test.ts

@@ -384,7 +384,7 @@ for (const skillName of ['review', 'ship']) {
 
   test(`${skillName} clarity: the state-machine signal checks the detector's exit status and fails toward dispatch`, () => {
     const block = between(army, '### Detect stack and scope', '### Read specialist hit rates');
-    expect(block).toContain(`source <(${HOST_PATHS.claude.binDir}/gstack-state-matrix detect --base <base> || echo SCOPE_STATE_MACHINE=unknown)\n`);
+    expect(block).toContain(`_SM=$(${HOST_PATHS.claude.binDir}/gstack-state-matrix detect --base <base>) || _SM=SCOPE_STATE_MACHINE=unknown; source <(echo "$_SM")\n`);
     expect(block.indexOf('SCOPE_STATE_MACHINE=unknown')).toBeLessThan(block.indexOf("set | grep '^SCOPE_'"));
     const selection = between(army, '### Select specialists', '### Adaptive gating').replace(/\s+/g, ' ');
     expect(selection).toContain('9. **State Machines** — if SCOPE_STATE_MACHINE is true or unknown (printed by the scope block)');
@@ -407,6 +407,12 @@ for (const skillName of ['review', 'ship']) {
       expect(failed.stdout).not.toMatch(/^SCOPE_STATE_MACHINE=false$/m);
       expect(failed.stderr).toContain('detector crashed');
       expect(run('exit 127').stdout).toMatch(/^SCOPE_STATE_MACHINE=unknown$/m);
+      const silent = run("echo 'detector found no git' >&2; exit 3");
+      expect(silent.stdout).toMatch(/^SCOPE_STATE_MACHINE=unknown$/m);
+      expect(silent.stderr).toContain('detector found no git');
+      const lateFail = run("echo SCOPE_STATE_MACHINE=true; echo SCOPE_LEAK=1; exit 1");
+      expect(lateFail.stdout).toMatch(/^SCOPE_STATE_MACHINE=unknown$/m);
+      expect(lateFail.stdout).not.toContain('SCOPE_LEAK');
       const detected = run("echo SCOPE_STATE_MACHINE=true; echo '# state-machine: src/takes.ts:4 proposal,accept'");
       expect(detected.stdout).toMatch(/^SCOPE_STATE_MACHINE=true$/m);
       expect(detected.stdout).toMatch(/^SCOPE_FRONTEND=false$/m);