rename project from SimpleshopTheme to Berrypod

All modules, configs, paths, and references updated.
836 tests pass, zero warnings.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/berrypod.ex

@@ -0,0 +1,9 @@
+defmodule Berrypod do
+  @moduledoc """
+  Berrypod keeps the contexts that define your domain
+  and business logic.
+
+  Contexts are also responsible for managing your data, regardless
+  if it comes from the database, an external API or others.
+  """
+end