backup: fix timers after boot, prepare steamdeck

hosts/steamdeck/hardware-configuration.nix

@@ -74,9 +74,42 @@
                       };
                   };
               };
+#              bak = {
+#                  onCalendar = "daily";
+#                  settings = {
+#	              stream_buffer = "256m";
+#                      stream_compress = "lz4";
+#                      incremental = "yes";
+#                      snapshot_create = "no";
+#                      snapshot_dir = "@snapshots";
+#                      timestamp_format = "long";
+#
+#                      snapshot_preserve_min = "all";
+#                      target_preserve_min = "no";
+#                      target_preserve = "2m 4w 3d";
+#
+#                      ssh_identity = "/etc/btrbk/ssh/id_ed25519_btrbk_nas";
+#                      ssh_user = "btrbk";
+#                    
+#                      volume =  {
+#                          "/mnt/snapshots/root" = {
+#                              subvolume = {
+#                                  "@home" = {};
+#                              };
+#	                      target = "ssh://jupiter.home.opel-online.de:2220/mnt/snapshots/Mars/@snapshots/@steamdeck";
+#                          };
+#                      };
+#	          };
+#	      };
           };
       };
   };
+#
+#  systemd.timers = {
+#      btrbk-bak = {
+#          requires = [ "network-online.target" ];
+#      };
+#  };
 
   fileSystems."/" =
     { device = "/dev/mapper/crypted";