backups: Add atomic backups with restic

configuration/services/starbound.nix

@@ -110,4 +110,12 @@ in {
       # ProtectHome = "read-only"; # See further up
     };
   };
+
+  services.backups.starbound = {
+    user = "root";
+    paths = [
+      "/var/lib/private/starbound/storage/universe/"
+    ];
+    pauseServices = ["starbound.service"];
+  };
 }