feat: nix-host updates

- set up minimal fhs
- use root, things work with it
- add cache note
- correct ordering of `PATH`

flake.nix

@@ -64,24 +64,28 @@
             tag = "latest";
 
             runAsRoot = ''
-              ${dockerTools.shadowSetup}
+              mkdir /etc
-              useradd -m -s /run/current-system/sw/bin/bash docker-ci
+              # ${pkgs.shadow}/bin/useradd -m -s /run/current-system/sw/bin/bash docker-ci
+
+              chmod 777 /tmp
+              mkdir -p /var/tmp
+              chmod 777 /var/tmp
             '';
 
             # volumes to mount
             # -v /nix:/nix:ro
             # -v /run/current-system:/run/current-system
+            # -v /var/cache/docker-ci:/.cache
             # -v ${pkgs.buildEnv ... }:/run/container-env
             config = {
               Entrypoint = [ "/run/current-system/sw/bin/bash" ];
-              User = "1000:1000";
+              # User = "1000:1000";
               Env = [
                 "NIX_REMOTE=daemon"
                 "PATH=${lib.concatStringsSep ":" [
+                "/run/container-env/bin"
                 "/run/current-system/sw/bin"
                 "/run/current-system/sw/sbin"
-                "/run/container-env/bin"
-                # "/run/container-env/sbin" # This might not be needed
               ]}"
 
                 "SSL_CERT_FILE=/run/current-system/etc/ssl/certs/ca-bundle.crt"