Closes #478 The mode option of fs.writeFile does not reliably apply permissions on all filesystems. On Synology NAS Docker volumes (btrfs), the file ends up with 0755 permissions instead of 0600, causing SSH to refuse the key.
* refactor: extract restic in core package * chore: add turbo task runner * refactor: split server utils * chore: simplify withDeps signature and fix non-null assertion