Architecture & Design: Exposition of hash to help differential update

[EdouardVanbelle]

@DioCrafts How to you handle changes and update changed files from OxiCloud-desktop ?

I have seen that etag (the blake3 hash of the blob) is exposed in WebDav but not in API
are you using this entry ?

Woud it be interesting to expose it for better reconciliation cliet <-> server ?

/api/dedup/check is restricted for security and we could migrate it into an internal if necessary