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_web/controllers/error_preview_controller.ex

@@ -0,0 +1,20 @@
+defmodule BerrypodWeb.ErrorPreviewController do
+  @moduledoc """
+  Development-only controller for previewing error pages.
+  """
+  use BerrypodWeb, :controller
+
+  def not_found(conn, _params) do
+    conn
+    |> put_status(:not_found)
+    |> put_view(BerrypodWeb.ErrorHTML)
+    |> render("404.html")
+  end
+
+  def server_error(conn, _params) do
+    conn
+    |> put_status(:internal_server_error)
+    |> put_view(BerrypodWeb.ErrorHTML)
+    |> render("500.html")
+  end
+end