new-clan: update template and add test

checks/impure/flake-module.nix

@@ -1,5 +1,5 @@
 { self, ... }: {
-  perSystem = { pkgs, lib, ... }:
+  perSystem = { pkgs, lib, self', ... }:
     let
       impureChecks = {
         check-clan-template = pkgs.writeShellScriptBin "check-clan-template" ''
@@ -9,6 +9,8 @@
           trap "${pkgs.coreutils}/bin/chmod -R +w '$TMPDIR'; ${pkgs.coreutils}/bin/rm -rf '$TMPDIR'" EXIT
           export PATH="${lib.makeBinPath [
             pkgs.gitMinimal
+            pkgs.gnugrep
+            pkgs.jq
             pkgs.openssh
             pkgs.nix
           ]}"
@@ -18,8 +20,21 @@
           echo initialize new clan
           nix flake init -t ${self}#new-clan
 
+          echo override clan input to the current version
+          nix flake lock --override-input clan-core ${self}
+          nix flake lock --override-input nixpkgs ${self.inputs.nixpkgs}
+
           echo ensure flake outputs can be listed
           nix flake show
+
+          echo create a machine
+          ${self'.packages.clan-cli}/bin/clan machines create machine1
+
+          echo check machine1 exists
+          ${self'.packages.clan-cli}/bin/clan machines list | grep -q machine1
+
+          echo check machine1 appears in nixosConfigurations
+          nix flake show --json | jq '.nixosConfigurations' | grep -q machine1
         '';
       };
     in