refactor: dedup several modules by breaking them out into feature modules

hosts/shared/darwin.nix

@@ -1,38 +1,12 @@
 { self, pkgs, ... }:
 {
+  imports = [
+    ./nix-package-manager.nix
+  ];
+
   # Only use homebrew for casks.
   homebrew.enable = true;
 
-  nix = {
-    gc = {
-      automatic = true;
-      interval = {
-        Hour = 3;
-        Minute = 15;
-        Weekday = 7;
-      };
-      options = "--delete-older-than 30d";
-    };
-
-    optimise = {
-      automatic = true;
-      interval = {
-        Hour = 3;
-        Minute = 15;
-        Weekday = 7;
-      };
-    };
-
-    settings = {
-      experimental-features = [
-        "nix-command"
-        "flakes"
-      ];
-
-      use-xdg-base-directories = true;
-    };
-  };
-
   # Enables Touch ID for sudo prompts.
   security.pam.services.sudo_local.touchIdAuth = true;
 
@@ -45,21 +19,23 @@
 
       interactiveShellInit = ''
         eval "$(jump shell)"
+        eval "$(devenv hook zsh)"
+        clear;fastfetch
       '';
     };
   };
 
   environment = {
-    shellAliases = import ../../features/aliases.nix { inherit pkgs; };
-    variables = import ../../features/xdg.nix { inherit pkgs; };
+    shellAliases = import ../../features/aliases.nix { };
+    variables = import ../../features/xdg.nix { };
 
     systemPackages = with pkgs; [
       wget
-      fastfetch
       btop
       nerd-fonts.hack
-      jump
+      devenv
       ripgrep
+      fastfetch
     ];
   };