split home-manager into their own submodules

modules/dev/nix/nixos.nix

@@ -0,0 +1,30 @@
+{
+  config,
+  inputs,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  nix = import ./common.nix {
+    inherit pkgs;
+    inherit (config.networking) hostName;
+  };
+in
+{
+  options = {
+    my.dev.nix = {
+      enable = lib.mkEnableOption "Install Nix tooling globally";
+      users = lib.mkOption {
+        type = inputs.self.lib.usersOptionType lib;
+        default = config.my.toggleUsers.dev;
+        description = "Users to install Nix packages for";
+      };
+    };
+    devShells.nix = lib.mkOption {
+      type = lib.types.package;
+      default = nix.devShell;
+      description = "Nix/NixOS development shell with formatter, linter, LSP, and Cachix";
+    };
+  };
+}