🐛 fix(thirdparty): preserve optional manifest fields

tests/test_thirdparty_skills_pipeline.py

@@ -92,6 +92,12 @@ class ThirdpartySkillsPipelineTests(unittest.TestCase):
             text.index('git checkout -B "$TARGET_BRANCH" "origin/$TARGET_BRANCH"'),
         )
 
+    def test_sync_script_uses_non_whitespace_separator_for_optional_fields(self):
+        text = SYNC_SCRIPT.read_text(encoding="utf-8")
+        self.assertIn('"\\x1f".join(', text)
+        self.assertIn("while IFS=$'\\x1f' read -r", text)
+        self.assertNotIn("while IFS=$'\\t' read -r", text)
+
 
 if __name__ == "__main__":
     unittest.main()