Deduplication on tart push?

[fkorotkov]

Discussed in #884

^{Originally posted by andrewhamon August 7, 2024}
I've noticed the deduplication when doing tart pulls -- this is awesome! I usually see about 70% deduplication which is major.

I was wondering if its possible to deduplicate on tart push as well? Not sure how the deduping works, is it based on the manifest and layer hashes, or does it require access to a fully constructed disk img? If its layer based, it seems like it should be feasible to not push layers which already exist.