fix: NixOS | add persist subvolumes for btrfs in disko

nixos/disko-config.nix

@@ -45,6 +45,10 @@
                       mountpoint = "/var/log";
                       mountOptions = ["subvol=log" "compress=zstd" "noatime"];
                     };
+                    "/persist" = {
+                      mountpoint = "/persist";
+                      mountOptions = ["subvol=persist" "compress=zstd" "noatime"];
+                    };
                     "/swap" = {
                       mountpoint = "/swap";
                       swap.swapfile.size = "64G";
@@ -58,4 +62,7 @@
       };
     };
   };
+
+  fileSystems."/persist".neededForBoot = true;
+  fileSystems."/var/log".neededForBoot = true;
 }