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/page_editor_hook.ex

@@ -61,6 +61,9 @@ defmodule BerrypodWeb.PageEditorHook do
       |> assign(:theme_editor_contrast_warning, :ok)
       |> assign(:theme_editor_customise_open, false)
       |> assign(:theme_editor_presets, Presets.all_with_descriptions())
+      # Settings editing state
+      |> assign(:settings_dirty, false)
+      |> assign(:settings_save_status, :idle)
       |> attach_hook(:editor_params, :handle_params, &handle_editor_params/3)
       |> attach_hook(:editor_events, :handle_event, &handle_editor_event/3)
       |> attach_hook(:editor_info, :handle_info, &handle_editor_info/2)
@@ -212,6 +215,16 @@ defmodule BerrypodWeb.PageEditorHook do
                 load_theme_state(socket)
               end
 
+            # Initialize settings form from current page if not already set
+            # Only custom pages have editable settings (meta_description, published, etc.)
+            socket =
+              if is_nil(socket.assigns[:settings_form]) && socket.assigns[:page] &&
+                   socket.assigns.page[:type] == "custom" do
+                init_settings_form(socket)
+              else
+                socket
+              end
+
             assign(socket, :editor_active_tab, :settings)
         end
 
@@ -251,6 +264,15 @@ defmodule BerrypodWeb.PageEditorHook do
     end
   end
 
+  # Settings editing events (custom page settings)
+  defp handle_editor_event("settings_" <> action, params, socket) do
+    if socket.assigns.is_admin do
+      handle_settings_action(action, params, socket)
+    else
+      {:cont, socket}
+    end
+  end
+
   defp handle_editor_event(_event, _params, socket), do: {:cont, socket}
 
   # ── Block manipulation actions ───────────────────────────────────
@@ -721,6 +743,106 @@ defmodule BerrypodWeb.PageEditorHook do
   # Catch-all for unknown theme actions
   defp handle_theme_action(_action, _params, socket), do: {:halt, socket}
 
+  # ── Settings editing actions (custom page settings) ────────────────
+
+  # Validate page settings form (live as-you-type)
+  defp handle_settings_action("validate_page", %{"page" => params}, socket) do
+    page = socket.assigns.page
+
+    # Only allow editing custom pages
+    if page && page.type == "custom" do
+      socket =
+        socket
+        |> assign(:settings_form, params)
+        |> assign(:settings_dirty, has_settings_changed?(page, params))
+        |> assign(:settings_save_status, :idle)
+
+      {:halt, socket}
+    else
+      {:halt, socket}
+    end
+  end
+
+  # Save page settings
+  defp handle_settings_action("save_page", %{"page" => params}, socket) do
+    page = socket.assigns.page
+
+    # Only allow editing custom pages
+    if page && page.type == "custom" do
+      # Normalize checkbox fields (unchecked checkboxes aren't sent)
+      params =
+        params
+        |> Map.put_new("published", "false")
+        |> Map.put_new("show_in_nav", "false")
+
+      old_slug = page.slug
+
+      # Fetch the Page struct from DB (assigns.page may be a map from cache)
+      page_struct = Pages.get_page_struct(page.slug)
+
+      case Pages.update_custom_page(page_struct, params) do
+        {:ok, updated_page} ->
+          # Reinitialize form from saved page
+          socket =
+            socket
+            |> assign(:page, updated_page)
+            |> assign(:settings_form, nil)
+            |> assign(:settings_dirty, false)
+            |> assign(:settings_save_status, :saved)
+
+          # Reinit form with new page values
+          socket = init_settings_form(socket)
+
+          # If slug changed, redirect to new URL
+          socket =
+            if updated_page.slug != old_slug do
+              push_navigate(socket, to: "/#{updated_page.slug}")
+            else
+              socket
+            end
+
+          {:halt, socket}
+
+        {:error, _changeset} ->
+          socket = assign(socket, :settings_save_status, :error)
+          {:halt, socket}
+      end
+    else
+      {:halt, socket}
+    end
+  end
+
+  # Catch-all for unknown settings actions
+  defp handle_settings_action(_action, _params, socket), do: {:halt, socket}
+
+  # Check if settings have changed from current page values
+  defp has_settings_changed?(page, params) do
+    page.title != (params["title"] || "") or
+      page.slug != (params["slug"] || "") or
+      (page.meta_description || "") != (params["meta_description"] || "") or
+      to_string(page.published) != (params["published"] || "false") or
+      to_string(page.show_in_nav) != (params["show_in_nav"] || "false") or
+      (page.nav_label || "") != (params["nav_label"] || "") or
+      to_string(page.nav_position || 0) != (params["nav_position"] || "0")
+  end
+
+  # Initialize settings form from page values
+  defp init_settings_form(socket) do
+    page = socket.assigns.page
+
+    form = %{
+      "title" => page.title || "",
+      "slug" => page.slug || "",
+      "meta_description" => page.meta_description || "",
+      "published" => to_string(page.published),
+      "show_in_nav" => to_string(page.show_in_nav),
+      "nav_label" => page.nav_label || "",
+      "nav_position" => to_string(page.nav_position || 0)
+    }
+
+    assign(socket, :settings_form, form)
+  end
+
   # Helper to update a theme setting and regenerate CSS
   defp update_theme_setting(socket, attrs, field) do
     case Settings.update_theme_settings(attrs) do