When PyYAML is unavailable or YAML frontmatter is malformed, the fallback
parser may return metadata as a string instead of a dict. This causes
AttributeError when calling .get("hermes") on the string.
Added explicit type checks to handle cases where metadata or hermes fields
are not dicts, preventing the crash.
Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>