Download target changes after editing metadata

[pgwillia]

Describe the bug

It links to https://era.library.ualberta.ca/items/b0368001-8f63-4786-b994-1cf88fcfc826/download/c2fc73ae-c3f3-4b9b-8113-4130ee04d290 which is not a thing, hence the 404.

The item looks fine https://era.library.ualberta.ca/items/b0368001-8f63-4786-b994-1cf88fcfc826

And the download is fine too https://era.library.ualberta.ca/items/b0368001-8f63-4786-b994-1cf88fcfc826/download/921733ec-d539-40b5-a564-835260a82ea2

So what seems to be happening is that when any edit is made to an item, the files are given new identifiers, invalidating any existing links, like the one in Google Scholar.

To Reproduce
Steps to reproduce the behavior:

1. Go to an item (any item)
2. View the files in a separate tab
3. Make an edit (doesn't seem to matter where the edit is made)
4. Finish the wizard and click save
5. Refresh the files being viewed in a separate tab. You'll notice that the target URL for downloads has a new identifier.

Expected behavior

• If the files aren't substantially changed, the download URL will persist between saves to the item.
• Is it possible to restore old identifiers so that Google Scholar links work again?

Additional context
Some oddity I could investigate is the metadata about the item we're displaying for google scholar.

https://search.google.com/search-console/index?resource_id=https://era.library.ualberta.ca/&utm_source=wnc_20237597&utm_medium=gamma&utm_campaign=wnc_20237597&utm_content=msg_110624660&hl=en-CA has been reporting broken links

[pgwillia]

I think the bug comes from line 159 where we assign a random fileset_uuid

jupiter/app/models/draft_item.rb

Lines 149 to 160 in f04a470

	# reset files if the files have changed in Fedora outside of the draft process
	# NOTE: destroy the attachment record, DON'T use #purge, which will wipe the underlying blob shared with the
	# published item's shim
	files.each(&:destroy) if item.files.present?
	# add an association between the same underlying blobs the Item uses and the Draft
	item.files_attachments.each do |attachment|
	ActiveStorage::Attachment.create(record: self,
	blob: attachment.blob,
	name: :files,
	fileset_uuid: UUIDTools::UUID.random_create)
	end

But I think that demonstrates that we could restore the old uuid from Google Scholar.