Add most-used dev tools, sshd/firewall, bash+liquidprompt shell

modules/home/dev-tools.nix provisions the developer's evidenced most-
used CLI/client tooling (gh, tmux, htop, yq-go, tree-sitter, docker,
docker-compose, kubectl, awscli2). modules/home/shell.nix drops zsh/
starship/direnv in favor of bash + liquidprompt, both left entirely to
the user's own dotfiles for config since home-manager can't own
~/.bashrc without conflicting with it. modules/nixos/common.nix adds
sshd (key-only auth) and a firewall baseline for future NixOS hosts.

1 files changed, 14 insertions, 3 deletions

diff --git a/modules/nixos/common.nix b/modules/nixos/common.nix
index 5427414..2e70b15 100644
--- a/modules/nixos/common.nix
+++ b/modules/nixos/common.nix
@@ -13,11 +13,22 @@
   time.timeZone = lib.mkDefault "Etc/UTC";
   i18n.defaultLocale = lib.mkDefault "en_US.UTF-8";
 
-  programs.zsh.enable = true;
-
   users.users.tom = {
     isNormalUser = true;
     extraGroups = [ "wheel" ];
-    shell = pkgs.zsh;
+    shell = pkgs.bash;
+  };
+
+  services.openssh = {
+    enable = true;
+    settings = {
+      PasswordAuthentication = false;
+      PermitRootLogin = "no";
+    };
+  };
+
+  networking.firewall = {
+    enable = true;
+    allowedTCPPorts = [ 22 ];
   };
 }