When correctness is important I much prefer having strong types for most primitives, such that the name is focused on describing semantics of the use, and the type on how it is represented:

    struct FileNode {
        parent: NodeIndex<FileNode>,
        content_header_offset: ByteOffset,
        file_size: ByteCount,
    }

Strong typing of primitives also help prevent bugs like mixing up parameter ordering etc.

I agree. Including the unit in the name is a form of Hungarian notation; useful when the language doesn't support defining custom types, but looks a little silly otherwise.