Function seal_snapshot_directory 

pub fn seal_snapshot_directory(
    dir: &Path,
    algorithm: u32,
) -> Result<SealStats, FsVerityError>

Seal all files in a directory tree with fs-verity.

Walks the directory recursively and calls seal_with_fsverity on each regular file. Stops trying if the filesystem doesn’t support verity (detected on the first file).