zsh: init zsh module

hosts/cityseventeen/apps.nix

@@ -28,19 +28,18 @@ in
       direnv.enable = true;
       openssh.enable = true;
     };
+    shells.zsh = {
+      enable = true;
+      package = pkgs.amadaluzian-zsh;
+    };
     system.pipewire.enable = true;
     wms.niri.enable = true;
   };
 
-  programs = {
-    git = {
+  programs.git = {
     enable = true;
     package = pkgs.gitFull;
   };
-    zsh = {
-      enable = true;
-    };
-  };
 
   services = {
     deluge = {

hosts/shared/zsh.nix

@@ -0,0 +1,31 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.alqueva.shells.zsh;
+
+  inherit (lib.modules) mkIf;
+  inherit (lib.options) mkEnableOption mkPackageOption;
+in
+{
+  options.alqueva.shells.zsh = {
+    enable = mkEnableOption "zsh";
+    package = mkPackageOption pkgs "zsh" { };
+  };
+  config = mkIf cfg.enable {
+    environment = {
+      systemPackages = [ cfg.package ];
+      shells = [ cfg.package ];
+    };
+
+    programs.zsh = {
+      enable = true;
+      enableCompletion = true;
+      syntaxHighlighting.enable = true;
+      autosuggestions.enable = true;
+    };
+  };
+}