feat: add 'azure' cloud option (and generalized module)

home/modules/cloud/azure.nix

@@ -0,0 +1,12 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  config = lib.mkIf config.cloud.azure.enable {
+    home.packages = with pkgs; [ azure-cli ];
+  };
+}

home/modules/cloud/default.nix

@@ -0,0 +1,17 @@
+{ lib, ... }:
+
+{
+  options.cloud = {
+    azure = {
+      enable = lib.mkEnableOption "azure CLI";
+    };
+    hetzner = {
+      enable = lib.mkEnableOption "hetzner CLI";
+    };
+  };
+
+  imports = [
+    ./azure.nix
+    ./hetzner.nix
+  ];
+}

home/modules/cloud/hetzner.nix

@@ -0,0 +1,21 @@
+{
+  config,
+  lib,
+  pkgs,
+  osConfig ? null,
+  ...
+}:
+
+let
+  isNixOS = osConfig != null;
+in
+{
+  config = lib.mkIf config.cloud.hetzner.enable {
+    warnings =
+      lib.optional (!isNixOS)
+        "hcloud module requires NixOS host configuration. This module will not work with standalone home-manager.";
+    home = {
+      packages = with pkgs; [ hcloud ];
+    };
+  };
+}