refactor(elixir): hierarchical refactor

to extract common code patterns from
category/storage location systems

lib/components_elixir/inventory/hierarchical_schema.ex

@@ -0,0 +1,41 @@
+defmodule ComponentsElixir.Inventory.HierarchicalSchema do
+  @moduledoc """
+  Behaviour for schemas that implement hierarchical relationships.
+
+  Provides a contract for entities with parent-child relationships,
+  ensuring consistent interface across different hierarchical entities.
+  """
+
+  @doc """
+  Returns the full hierarchical path as a string.
+  Example: "Electronics > Components > Resistors"
+  """
+  @callback full_path(struct()) :: String.t()
+
+  @doc """
+  Returns the parent entity or nil if this is a root entity.
+  """
+  @callback parent(struct()) :: struct() | nil
+
+  @doc """
+  Returns the children entities as a list.
+  """
+  @callback children(struct()) :: [struct()]
+
+  @doc """
+  Returns the separator used for path display.
+  """
+  @callback path_separator() :: String.t()
+
+  @doc """
+  Returns the entity type for use with the Hierarchical module.
+  """
+  @callback entity_type() :: atom()
+
+  defmacro __using__(_opts) do
+    quote do
+      @behaviour ComponentsElixir.Inventory.HierarchicalSchema
+      alias ComponentsElixir.Inventory.Hierarchical
+    end
+  end
+end