add settings editor component for unified on-site editing

Phase 3b of unified editing mode. The Settings tab now shows
context-specific forms: custom pages get editable title, slug,
meta, visibility and nav options; system pages get read-only info
with links to admin; product/collection pages show provider info.

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

lib/berrypod_web/components/shop_components.ex

@@ -10,6 +10,7 @@ defmodule BerrypodWeb.ShopComponents do
   - `Product` — product cards, gallery, variant selector, hero sections
   - `Content` — rich text, responsive images, contact form, reviews
   - `ThemeEditor` — shared theme editor components for admin and on-site editing
+  - `SettingsEditor` — shared settings editor components for on-site editing
   """
 
   defmacro __using__(_opts \\ []) do
@@ -19,6 +20,7 @@ defmodule BerrypodWeb.ShopComponents do
       import BerrypodWeb.ShopComponents.Content
       import BerrypodWeb.ShopComponents.Layout
       import BerrypodWeb.ShopComponents.Product
+      import BerrypodWeb.ShopComponents.SettingsEditor
       import BerrypodWeb.ShopComponents.ThemeEditor
     end
   end