home-manager/state: init module

modules/home-manager/_private/default.nix

@@ -1,6 +1,7 @@
 {
   imports = [
     ./extra-arguments.nix
+    ./state.nix
     ./suites/desktop.nix
     ./suites/dev.nix
     ./suites/editors.nix

modules/home-manager/_private/state.nix

@@ -0,0 +1,37 @@
+{ lib, ... }:
+
+{
+  options.state = lib.mkOption {
+    type = lib.types.submodule {
+      freeformType = with lib.types; attrsOf anything;
+      options = {
+        ignoreDirectories = lib.mkOption {
+          type = with lib.types; listOf str;
+          description = ''
+            A state variable holding a list of directory names to be excluded
+            in processes involving walking through directories (e.g., desktop
+            indexing).
+          '';
+          default = [ ];
+          example = [
+            "node_modules"
+            ".direnv"
+          ];
+        };
+      };
+    };
+    description = ''
+      A set of values to be held in the home-manager configuration. Pretty much
+      used for anything that requires consistency or deduplicate the source of
+      truth for module values.
+    '';
+    example = {
+      sampleValue = 10;
+      dev.ignoreDirectories = [
+        ".git"
+        "node_modules"
+        ".direnv"
+      ];
+    };
+  };
+}