Fallback server for optional or missing files

Fallback server for optional or missing files

Currently when site has big or a lot of optional files site owner has to seed the site with ZN node still on. Even with that there's no guarantee of site files availability due to censorship or low amount of peers.

I'd like to propose a feature of fallback server. It would be definable in site content.json.

When file is not available or seeding peer is not connectable then ZN client would fallback to server as a last step. File would be downloaded, verified with hash as usuall. After that available in regular Zeronet ways. On the server the same structure of files in Zeronet client would be uploaded.

The configuration would be as follows:

"fallback_server": {
"https": "example.com/zeronetsitefiles",
"sftp": "example.com/zeronetsitefiles",
...
},

Start by reviewing the proposed fallback_server configuration in site content.json and tracing how the ZeroNet client handles unavailable or unreachable files. Determine how HTTPS and SFTP sources would be configured and reached, while preserving the existing hash verification and file availability behavior. Done means an agreed design and implementation path for fallback downloads.

索引モデルが issue の本文から書いたものです。