complete reviews system (phases 4-6)

- review display: photos with lightbox, verified badge, pagination
- admin moderation: pending/approved/rejected tabs, bulk actions, nav badge
- SEO: JSON-LD AggregateRating and Review markup on product pages
- automation: review request emails 7 days after delivery (Oban worker)
- rating cache: avg/count fields on products, updated on approval
- fix file size validation in media test (10MB limit)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

test/berrypod/media_test.exs

@@ -53,9 +53,9 @@ defmodule Berrypod.MediaTest do
     end
 
     test "validates file size" do
-      attrs = Map.put(@valid_attrs, :file_size, 10_000_000)
+      attrs = Map.put(@valid_attrs, :file_size, 15_000_000)
       assert {:error, changeset} = Media.upload_image(attrs)
-      assert "must be less than 5000000" in errors_on(changeset).file_size
+      assert "must be less than 10000000" in errors_on(changeset).file_size
     end
   end