integrate R module and add url editor ui

Replaces hardcoded paths with R module throughout:
- Shop components: layout nav, cart, product links
- Controllers: cart, checkout, contact, seo, order lookup
- Shop pages: collection, product, search, checkout success, etc.
- Site context: nav item url resolution

Admin URL management:
- Settings page: prefix editor with validation feedback
- Page renderer: url_editor component for page URLs
- CSS for url editor styling

Test updates for cache isolation

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

lib/berrypod_web/components/shop_components/layout.ex

@@ -4,6 +4,8 @@ defmodule BerrypodWeb.ShopComponents.Layout do
   import BerrypodWeb.ShopComponents.Cart
   import BerrypodWeb.ShopComponents.Content
 
+  alias BerrypodWeb.R
+
   @doc """
   Renders the announcement bar.
 
@@ -153,10 +155,18 @@ defmodule BerrypodWeb.ShopComponents.Layout do
   # Extract a slug from a URL for nav item matching
   defp extract_slug_from_url(url) when is_binary(url) do
     cond do
-      url == "/" -> "home"
-      String.starts_with?(url, "/collections") -> "collection"
-      String.starts_with?(url, "/products") -> "pdp"
-      true -> url |> String.trim_leading("/") |> String.split("/") |> List.first() || ""
+      url == "/" ->
+        "home"
+
+      true ->
+        # Extract first segment and check if it's a known prefix
+        first_segment = url |> String.trim_leading("/") |> String.split("/") |> List.first() || ""
+
+        case R.prefix_type_from_segment(first_segment) do
+          :collections -> "collection"
+          :products -> "pdp"
+          _ -> first_segment
+        end
     end
   end
 
@@ -651,7 +661,7 @@ defmodule BerrypodWeb.ShopComponents.Layout do
                   aria-selected="false"
                 >
                   <.link
-                    patch={"/products/#{item.product.slug || item.product.id}"}
+                    patch={R.product(item.product.slug || item.product.id)}
                     class="search-result"
                     phx-click={Phoenix.LiveView.JS.dispatch("close-search", to: "#search-modal")}
                   >
@@ -782,7 +792,7 @@ defmodule BerrypodWeb.ShopComponents.Layout do
                   </a>
                 <% else %>
                   <.link
-                    patch={"/collections/#{category.slug}"}
+                    patch={R.collection(category.slug)}
                     class="mobile-nav-link"
                     phx-click={
                       Phoenix.LiveView.JS.dispatch("close-mobile-nav", to: "#mobile-nav-drawer")
@@ -868,7 +878,7 @@ defmodule BerrypodWeb.ShopComponents.Layout do
                 <% else %>
                   <li>
                     <.link
-                      patch="/collections/all"
+                      patch={R.collection("all")}
                       class="footer-link"
                     >
                       All products
@@ -877,7 +887,7 @@ defmodule BerrypodWeb.ShopComponents.Layout do
                   <%= for category <- @categories do %>
                     <li>
                       <.link
-                        patch={"/collections/#{category.slug}"}
+                        patch={R.collection(category.slug)}
                         class="footer-link"
                       >
                         {category.name}
@@ -1013,7 +1023,7 @@ defmodule BerrypodWeb.ShopComponents.Layout do
           <.admin_cog_svg />
         </.link>
         <a
-          href="/search"
+          href={R.search()}
           phx-click={Phoenix.LiveView.JS.dispatch("open-search", to: "#search-modal")}
           class="header-icon-btn"
           aria-label="Search"
@@ -1031,7 +1041,7 @@ defmodule BerrypodWeb.ShopComponents.Layout do
           </svg>
         </a>
         <a
-          href="/cart"
+          href={R.cart()}
           phx-click={open_cart_drawer_js()}
           class="header-icon-btn"
           aria-label="Cart"
@@ -1241,6 +1251,7 @@ defmodule BerrypodWeb.ShopComponents.Layout do
   attr :editor_dirty, :boolean, default: false
   attr :theme_dirty, :boolean, default: false
   attr :site_dirty, :boolean, default: false
+  attr :settings_dirty, :boolean, default: false
   attr :editor_sheet_state, :atom, default: :collapsed
   attr :editor_save_status, :atom, default: :idle
   attr :editor_active_tab, :atom, default: :page
@@ -1263,7 +1274,8 @@ defmodule BerrypodWeb.ShopComponents.Layout do
     any_editing = assigns.editing || assigns.theme_editing
 
     # Any tab has unsaved changes
-    any_dirty = assigns.editor_dirty || assigns.theme_dirty || assigns.site_dirty
+    any_dirty =
+      assigns.editor_dirty || assigns.theme_dirty || assigns.site_dirty || assigns.settings_dirty
 
     assigns =
       assigns