fix: wrong nvidia enable path in home-manager impermanence passthrough; and impermanence requires root home directory to be set separately

modules/config/impermanence.nix

@@ -49,7 +49,7 @@ in {
   # persistence options that we defined above.
   imports = let
     mkUserFiles = map (x:
-      {mode = "600";}
+      {parentDirectory.mode = "700";}
       // (
         if isAttrs x
         then x

users/common/impermanence.nix

@@ -1,8 +1,11 @@
 {
   config,
   nixosConfig,
+  lib,
   ...
-}: {
+}: let
+  inherit (lib) optionals;
+in {
   home.persistence."/state".files =
     [
       # nothing yet ...
@@ -28,7 +31,7 @@
       ".local/state/nvim"
       ".cache/nvim"
     ]
-    ++ optionals nixosConfig.hardware.nvidia.enable [
+    ++ optionals nixosConfig.hardware.nvidia.modesetting.enable [
       ".cache/nvidia" # GLCache
     ]
     ++ optionals nixosConfig.services.pipewire.enable [

users/root/default.nix

@@ -1,6 +1,5 @@
 {
   config,
-  lib,
   pkgs,
   ...
 }: {
@@ -10,6 +9,10 @@
     shell = pkgs.zsh;
   };
 
+  # This cannot currently be derived automatically due to a design flaw in nixpkgs.
+  environment.persistence."/state".users.root.home = "/root";
+  environment.persistence."/persist".users.root.home = "/root";
+
   home-manager.users.root = {
     imports = [
       ../common