feat: change iso to btrfs

iso/configuration.nix

@@ -1,5 +1,9 @@
-{ config, lib, pkgs, ... }: {
+{ config, lib, pkgs, ... }:
+let
+  impermanence = builtins.fetchTarball "https://github.com/nix-community/impermanence/archive/master.tar.gz";
+in {
 	imports = [
+    "${impermanence}/nixos.nix"
 		<nixpkgs/nixos/modules/profiles/all-hardware.nix>
 		<nixpkgs/nixos/modules/profiles/base.nix>
 		#installer-only ./hardware-configuration.nix
@@ -50,5 +54,34 @@
 		zip
 	];
 
+  environment.persistence."/nix/persist" = {
+    hideMounts = true;
+    directories = [
+      "/home"
+    ];
+  };
+  environment.persistence."/nix/persist/system" = {
+    hideMounts = true;
+    directories = [
+      "/etc/nixos"
+      "/root/.ssh"
+      "/var/bento"
+      "/var/log"
+      "/var/lib/bluetooth"
+      "/var/lib/docker"
+      "/var/lib/flatpak"
+      "/var/lib/fprint"
+      "/var/lib/nixos"
+      "/var/lib/mysql"
+      "/etc/NetworkManager/system-connections"
+    ];
+    files = [
+      { file = "/etc/ssh/ssh_host_ed25519_key"; parentDirectory = { mode = "u=rwx,g=,o="; }; }
+      { file = "/etc/ssh/ssh_host_ed25519_key.pub"; parentDirectory = { mode = "u=rwx,g=,o="; }; }
+      { file = "/etc/ssh/ssh_host_rsa_key"; parentDirectory = { mode = "u=rwx,g=,o="; }; }
+      { file = "/etc/ssh/ssh_host_rsa_key.pub"; parentDirectory = { mode = "u=rwx,g=,o="; }; }
+    ];
+  };
+
   system.stateVersion = "23.05"; # Did you read the comment?
 }