feat: USB recovery installer ISO (ssh key baked in) for headless reinstall

flake.nix

@@ -60,6 +60,25 @@
             })
           ];
         };
+
+        # Bootable USB recovery installer with our SSH key + sshd + DHCP.
+        # Build the ISO:
+        #   nix build .#nixosConfigurations.installer-iso.config.system.build.isoImage
+        # dd it to a USB stick, boot the ZimaBlade from it, SSH in, ./deploy install.
+        installer-iso = nixpkgs.lib.nixosSystem {
+          inherit system;
+          modules = [
+            (nixpkgs + "/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix")
+            ({ ... }: {
+              services.openssh.enable = true;
+              services.openssh.settings.PermitRootLogin = "prohibit-password";
+              users.users.root.openssh.authorizedKeys.keys = [
+                "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGZpkPVhzi1zG5JI9hWyUgdyvNIQbp4ts4jw3idpMhhN erik@laptop"
+              ];
+              networking.hostName = "jupiter-installer";
+            })
+          ];
+        };
       };
     };
 }