add site name separator to shop page titles

All shop pages now render as "Page · Store Name" using live_title suffix.
Home stays as "Home · Store Name" for consistency with live navigation.
Updated cart test to use regex for whitespace-tolerant title matching.

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

lib/berrypod_web/components/layouts/shop_root.html.heex

@@ -11,7 +11,9 @@
           "Welcome to #{@theme_settings.site_name}"
       }
     />
-    <.live_title>{assigns[:page_title] || @theme_settings.site_name}</.live_title>
+    <.live_title suffix={" · #{@theme_settings.site_name}"}>
+      {assigns[:page_title]}
+    </.live_title>
     <!-- Preload critical fonts for the current typography preset -->
     <%= for preload <- Berrypod.Theme.Fonts.preload_links(
           @theme_settings.typography,

test/berrypod_web/live/shop/cart_test.exs

@@ -112,7 +112,7 @@ defmodule BerrypodWeb.Shop.CartTest do
     test "page title is Cart", %{conn: conn} do
       {:ok, _view, html} = live(conn, ~p"/cart")
 
-      assert html =~ "<title>Cart</title>"
+      assert html =~ ~r/Cart\s*·\s*Store Name/
     end
   end
 end