refactor(system): flatten

inputs/system/modules/base/nix/default.nix

@@ -1,10 +1,49 @@
-{ lib, ... }:
+{ lib, config, pkgs, inputs, ... }:
+
+let
+  inherit (lib) mkIf mapAttrs mapAttrsToList;
+  host = config.systemModules.host;
+in
 
 {
   imports = [
-    ./nh
-    ./nix
-    ./nixpkgs
-    ./subs
+    ./nh.nix
+    ./nixpkgs.nix
+    ./subs.nix
   ];
+
+  config = mkIf (host.type != "phone") {
+    environment = {
+      systemPackages = with pkgs; [
+        git
+        deadnix
+        statix
+      ];
+      defaultPackages = [];
+      etc = {
+        "nix/flake-channels/nixpkgs".source = inputs.nixpkgs;
+        "nix/flake-channels/home-manager".source = inputs.nixpkgs;
+      };
+    };
+    nix = {
+      registry = mapAttrs (_: v: {flake = v;}) inputs;
+      nixPath = mapAttrsToList (key: value: "${key}=${value.to.path}") config.nix.registry;
+      optimise = {
+        automatic = true;
+        dates = [ "18:00" ];
+      };
+      gc = {
+        automatic = true;
+        dates = "Sun *-*-* 17:00";
+        options = "--delete-older-than 30d";
+      };
+      settings = {
+        flake-registry = "etc/nix/registry.json";
+        allowed-users = [ "root" "@wheel" ];
+        trusted-users = [ "root" "@wheel" ];
+        experimental-features = [ "nix-command" "flakes" ];
+        builders-use-substitutes = true;
+      };
+    };
+  };
 }