fix(#1698): use CRLF-safe split in codex-exec flags test

The lint-tests check (local/no-crlf-fragile-split) flagged splitting
readFileSync content on literal "\n". Use .split(/\r?\n/) for Windows
git-autocrlf portability.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/enh-773-codex-exec-automation-flags.test.cjs

@@ -113,7 +113,7 @@ describe('#1698 regression: codex review is captured via --output-last-message,
     'utf8'
   );
   const codexExecLines = workflow
-    .split('\n')
+    .split(/\r?\n/)
     .filter((line) => line.includes('codex exec') && !line.includes('codex exec --help'));
 
   test('every codex exec invocation captures the review via -o <FILE>', () => {