move options back out to their config files, improve documentation

modules/features/applications/cli/nh.nix

@@ -1,27 +1,43 @@
 { inputs, self, ... }: let
-  mkNhAttrs = flake: {
+  mkNhAttrs = config: {
     enable = true;
-    inherit flake;
-    clean = {
-      enable = true;
-      dates = "Sun 05:00";
-      extraArgs = "--keep 5 --keep-since 3d";
-    };
+    flake = config.info.rootPath;
+    clean = config.features.applications.cli.nh.clean;
   };
 in {
+  imports = [ (inputs.helpers.mkMirroredModulesFlakeModule "globalOptions" ({ lib, ... }: {
+    options.features.applications.cli.nh = {
+      enable = lib.mkEnableOption "NH: Yet another Nix CLI helper";
+      clean = {
+        enable = lib.mkEnableOption "automatic cleaning of the system with `nh clean`";
+        dates = lib.mkOption {
+          type = lib.types.str;
+          description = "This option defines when the cleaning job should run, in the format of [`systemd.time` calendar events](https://www.man7.org/linux/man-pages/man7/systemd.time.7.html#CALENDAR_EVENTS).";
+          default = "daily";
+          example = "Sun 05:00";
+        };
+        extraArgs = lib.mkOption {
+          type = lib.types.str;
+          description = "This option sets any extra arguments that should be passed to the `nh clean` command when it is called by this automated service.";
+          default = "--keep 10 --keep-since 7d";
+        };
+      };
+    };
+  })) ];
+
   flake.nixosModules.global = { pkgs, config, lib, ... }: {
     config = lib.mkIf (config.features.applications.cli.nh.enable) {
-      programs.nh = mkNhAttrs config.info.rootPath;
+      programs.nh = mkNhAttrs config;
 
       home-manager.users.grey = lib.mkIf (config.features.nixos.home-manager.enable) {
-        features.applications.cli.nh.enable = lib.mkDefault true;
+        features.applications.cli.nh = lib.mkDefault config.features.applications.cli.nh;
       };
     };
   };
 
   flake.homeModules.global = { pkgs, config, lib, ... }: {
     config = lib.mkIf (config.features.applications.cli.nh.enable && config.info.isStandalone) {
-      programs.nh = mkNhAttrs config.info.rootPath;
+      programs.nh = mkNhAttrs config;
     };
   };
 }