refactoring for iServer and isWorkstation: part 1

hosts/servers/common/boot.nix

@@ -1,5 +1,4 @@
 { pkgs, ... }:
 
 {
-  boot.kernelPackages = pkgs.linuxPackages_hardened;
 }

hosts/servers/common/nix.nix

@@ -1,13 +1,4 @@
 { inputs, ... }:
 
 {
-  environment.etc."channels/nixpkgs".source = inputs.nixpkgs-stable.outPath;
-
-  nix = {
-    registry.nixpkgs.flake = inputs.nixpkgs-stable;
-    nixPath = [
-      "nixpkgs=/etc/channels/nixpkgs"
-      "/nix/var/nix/profiles/per-user/root/channels"
-    ];
-  };
 }

hosts/servers/common/services.nix

@@ -1,8 +1,4 @@
 { ... }:
 
 {
-  services.tailscale = {
-    extraSetFlags = [ "--advertise-exit-node" ];
-    useRoutingFeatures = "server";
-  };
 }