rework system, programs, desktop, cli and base aspects

aspects/systems/server.nix

@@ -0,0 +1,36 @@
+{ inputs, ... }:
+
+{
+  flake.modules.nixos.server =
+    {
+      config,
+      lib,
+      pkgs,
+      ...
+    }:
+    {
+      boot = {
+        kernelPackages = pkgs.linuxPackages_hardened;
+        kernel.sysctl = {
+          "net.ipv4.ip_forward" = 1;
+          "net.ipv6.conf.all.forwarding" = 1;
+        };
+      };
+
+      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"
+        ];
+      };
+
+      services.tailscale = {
+        extraSetFlags = [ "--advertise-exit-node" ];
+        useRoutingFeatures = "server";
+      };
+
+    };
+}