wire simple pages to PageRenderer (stage 3)

Home, Content (about/delivery/privacy/terms), Contact, and ErrorHTML
now render through the generic PageRenderer instead of hardcoded
templates. Block wrapper divs enable CSS grid targeting. Featured
products block supports layout/card_variant/columns settings for
different page contexts. Contact page uses CSS grid on data-block-type
attributes for two-column layout.

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

test/berrypod_web/page_renderer_test.exs

@@ -66,7 +66,7 @@ defmodule BerrypodWeb.PageRendererTest do
     test "delivery page renders hero" do
       html = render_page("delivery", %{content_blocks: []})
 
-      assert html =~ "Delivery information"
+      assert html =~ "Delivery & returns"
     end
 
     test "privacy page renders hero" do
@@ -78,7 +78,7 @@ defmodule BerrypodWeb.PageRendererTest do
     test "terms page renders hero" do
       html = render_page("terms", %{content_blocks: []})
 
-      assert html =~ "Terms & conditions"
+      assert html =~ "Terms of service"
     end
 
     test "contact page renders hero, form, and sidebar blocks" do