feat: add 'devenv' home manager module

home/hosts/andromache/default.nix

@@ -16,6 +16,7 @@
     ../../modules/cloud
     ../../modules/comms
     ../../modules/desktop/niri
+    ../../modules/devenv
     ../../modules/direnv
     ../../modules/git
     ../../modules/k8s/k9s.nix

home/modules/devenv/default.nix

@@ -0,0 +1,4 @@
+{ pkgs, ... }:
+{
+  home.packages = [ pkgs.devenv ];
+}