fix(gbrain-detect): let --doctor's report drain before exit

process.exit() cut a large verdict off mid-pipe, so Step 5's jq read
truncated JSON and stopped on a healthy brain. Set exitCode instead.

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

bin/gstack-gbrain-detect

@@ -351,14 +351,6 @@ function main(): void {
 // callers — setup, bin/dev-setup, and `gstack-config gbrain-refresh` — can
 // decide whether to render the gbrain :user variant without duplicating the
 // JSON grep. Prints nothing on stdout.
-// --doctor: the full brain-health gate /setup-gbrain Step 5 runs. Prints the
-// DoctorVerdict as JSON and exits 0 iff brain_ok.
-if (process.argv.includes("--doctor")) {
-  const verdict = runDoctor([], 300_000);
-  process.stdout.write(JSON.stringify(verdict, null, 2) + "\n");
-  process.exit(verdict.brain_ok ? 0 : 1);
-}
-
 if (process.argv.includes("--is-ok")) {
   const noCache = process.env.GSTACK_DETECT_NO_CACHE === "1";
   const status = localEngineStatus({ noCache });
@@ -370,4 +362,13 @@ if (process.argv.includes("--is-ok")) {
   );
 }
 
-main();
+// --doctor: the full brain-health gate /setup-gbrain Step 5 runs. Prints the
+// DoctorVerdict as JSON and exits 0 iff brain_ok. exitCode, not process.exit:
+// exit() cuts off a large report still draining into a pipe.
+if (process.argv.includes("--doctor")) {
+  const verdict = runDoctor([], 300_000);
+  process.stdout.write(JSON.stringify(verdict, null, 2) + "\n");
+  process.exitCode = verdict.brain_ok ? 0 : 1;
+} else {
+  main();
+}

test/setup-gbrain-doctor-gate.test.ts

@@ -141,6 +141,17 @@ describe('gstack-gbrain-detect --doctor', () => {
     expect(JSON.parse(r.stdout)).toMatchObject({ brain_ok: false, brain_failures: ['pgvector'] });
   });
 
+  test('prints a large report whole through a pipe', () => {
+    const big = { status: 'healthy', checks: Array.from({ length: 3000 }, (_, i) => ({ ...check(`c${i}`, 'brain'), message: 'x'.repeat(60) })) };
+    const env = { ...caseEnv('all checks pass'), FAKE_DOCTOR_DIR: path.join(tmp, 'big') };
+    fs.mkdirSync(env.FAKE_DOCTOR_DIR, { recursive: true });
+    fs.writeFileSync(path.join(env.FAKE_DOCTOR_DIR, 'scoped.json'), JSON.stringify(big));
+    for (let i = 0; i < 3; i++) {
+      const r = spawnSync('bash', ['-c', `"${DETECT}" --doctor | cat`], { env, encoding: 'utf-8', timeout: 30_000 });
+      expect(JSON.parse(r.stdout).report.checks).toHaveLength(3000);
+    }
+  });
+
   test('exits 1 with the cause when doctor prints no JSON', () => {
     const r = spawnSync(DETECT, ['--doctor'], { env: caseEnv('doctor prints no JSON'), encoding: 'utf-8', timeout: 30_000 });
     expect(r.status).toBe(1);