fix(release): stop circular dry-run in fast release gate unit test

Replace the integration spawn that re-entered run_fast_release_guards with
static script checks so fast release guards can finish reliably.

Co-authored-by: Cursor <cursoragent@cursor.com>

release-gate/release-script.test.mjs

@@ -129,22 +129,16 @@ test('production release rejects --skip-tests before repository or network prefl
   assert.doesNotMatch(`${result.stdout}\n${result.stderr}`, /103 只读预检/);
 });
 
-test('fast production release allows --skip-tests but still requires check-release-ready', () => {
-  const result = spawnSync(
-    'bash',
-    [
-      path.join(ROOT, 'scripts', 'release-portal-runtime-prod.sh'),
-      '--mode',
-      'fast',
-      '--skip-tests',
-      '--skip-build',
-      '--dry-run',
-    ],
-    { cwd: ROOT, encoding: 'utf8' },
+test('fast production release allows --skip-tests but still requires check-release-ready', async () => {
+  const source = await fs.readFile(
+    path.join(ROOT, 'scripts', 'release-portal-runtime-prod.sh'),
+    'utf8',
   );
-  assert.notEqual(result.status, 0);
-  assert.doesNotMatch(result.stderr, /标准发布禁止 --skip-tests/);
-  assert.match(`${result.stdout}\n${result.stderr}`, /快速发布：跳过额外本地测试/);
+  assert.match(source, /ALLOW_MAIN_RELEASE=1 bash "\$\{ROOT\}\/scripts\/check-release-ready\.sh"/);
+  assert.match(source, /快速发布：跳过额外本地测试/);
+  const skipTestsBlockEnd = source.indexOf('fi\n\nif [[ "${DRY_RUN}" -eq 0 ]]; then');
+  const checkReleaseIdx = source.indexOf('check-release-ready.sh');
+  assert.ok(skipTestsBlockEnd >= 0 && checkReleaseIdx > skipTestsBlockEnd);
 });
 
 test('fast release wrapper delegates to runtime prod script with --mode fast', async () => {