Show and Tell: cocalc now uses rustic for all project backups, storage of rootfs images and transfer of large files

[williamstein]

I've been working on https://github.com/sagemathinc/cocalc-ai for the last year (try it for free at https://cocalc.ai). CoCalc uses rustic VERY heavily for:

• automated backups to Cloudflare R2 of all projects
• storage of rootfs images (similar to Docker OCI)
• transfer of large data between projects

I contributed a tiny PR adding better hardlink support, but otherwise rustic out-of-the-box has worked perfectly for this. We have also hit no bugs or crashes so far.