pub fn find_skill_root<R: Read + Seek>(
zip: &mut ZipArchive<R>,
) -> Result<String>Expand description
Find the directory prefix inside the archive that contains a SKILL.md
marker. Returns "" when the marker sits at the archive root.
Some archives zip the skill directory directly (code-review/SKILL.md),
others zip its contents (SKILL.md). This detects the common prefix so
extraction can strip it and land contents flat in target.