consolidate shop pages into unified LiveView for editor state persistence

Replace individual shop LiveViews with a single Shop.Page that dispatches
to page modules based on live_action. This enables patch navigation between
pages, preserving socket state (including editor state) across transitions.

Changes:
- Add Shop.Page unified LiveView with handle_params dispatch
- Extract page logic into Shop.Pages.* modules (Home, Product, Collection, etc.)
- Update router to use Shop.Page with live_action for all shop routes
- Change navigate= to patch= in shop component links
- Add maybe_sync_editing_blocks to reload editor state when page changes
- Track editor_page_slug to detect cross-page navigation while editing
- Fix picture element height when hover image disabled
- Extract ThemeEditor components for shared use

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

lib/berrypod_web/live/shop/page.ex

@@ -0,0 +1,154 @@
+defmodule BerrypodWeb.Shop.Page do
+  @moduledoc """
+  Unified shop LiveView that handles all shop pages.
+
+  Using a single LiveView enables `patch` navigation between pages,
+  preserving socket state (including editor state) across transitions.
+  """
+
+  use BerrypodWeb, :live_view
+
+  alias BerrypodWeb.Shop.Pages
+
+  # Map live_action atoms to page handler modules
+  @page_modules %{
+    home: Pages.Home,
+    product: Pages.Product,
+    collection: Pages.Collection,
+    cart: Pages.Cart,
+    contact: Pages.Contact,
+    search: Pages.Search,
+    orders: Pages.Orders,
+    order_detail: Pages.OrderDetail,
+    checkout_success: Pages.CheckoutSuccess,
+    custom_page: Pages.CustomPage,
+    # Content pages all use the same module
+    about: Pages.Content,
+    delivery: Pages.Content,
+    privacy: Pages.Content,
+    terms: Pages.Content
+  }
+
+  # Pages that need session data passed to init
+  @session_pages [:orders, :order_detail]
+
+  @impl true
+  def mount(_params, session, socket) do
+    # Store session for pages that need it (orders, order_detail)
+    {:ok, assign(socket, :_session, session)}
+  end
+
+  @impl true
+  def handle_params(params, uri, socket) do
+    action = socket.assigns.live_action
+    prev_action = socket.assigns[:_current_page_action]
+    module = @page_modules[action]
+
+    # Clean up previous page if needed (e.g., unsubscribe from PubSub)
+    socket = maybe_cleanup_previous_page(socket, prev_action)
+
+    socket =
+      if action != prev_action do
+        # Page type changed - call init
+        socket = assign(socket, :_current_page_action, action)
+
+        result =
+          if action in @session_pages do
+            module.init(socket, params, uri, socket.assigns._session)
+          else
+            module.init(socket, params, uri)
+          end
+
+        case result do
+          {:noreply, socket} -> socket
+          {:redirect, socket} -> socket
+        end
+      else
+        socket
+      end
+
+    # After page init, sync editor state if editing and page changed
+    socket = maybe_sync_editing_blocks(socket)
+
+    # Always call handle_params for URL changes
+    case module.handle_params(params, uri, socket) do
+      {:noreply, socket} -> {:noreply, socket}
+    end
+  end
+
+  # If editing and we navigated to a different page, reload editing_blocks
+  defp maybe_sync_editing_blocks(socket) do
+    page = socket.assigns[:page]
+    editing = socket.assigns[:editing]
+    editor_page_slug = socket.assigns[:editor_page_slug]
+
+    if editing && page && page.slug != editor_page_slug do
+      # Page changed while editing - reload editing state for the new page
+      allowed = Berrypod.Pages.BlockTypes.allowed_for(page.slug)
+      at_defaults = Berrypod.Pages.Defaults.matches_defaults?(page.slug, page.blocks)
+
+      socket
+      |> assign(:editing_blocks, page.blocks)
+      |> assign(:editor_page_slug, page.slug)
+      |> assign(:editor_dirty, false)
+      |> assign(:editor_at_defaults, at_defaults)
+      |> assign(:editor_history, [])
+      |> assign(:editor_future, [])
+      |> assign(:editor_expanded, MapSet.new())
+      |> assign(:editor_allowed_blocks, allowed)
+    else
+      socket
+    end
+  end
+
+  @impl true
+  def handle_event(event, params, socket) do
+    module = @page_modules[socket.assigns.live_action]
+
+    case module.handle_event(event, params, socket) do
+      :cont ->
+        # Event not handled by page module, let hooks handle it
+        {:noreply, socket}
+
+      {:noreply, socket} ->
+        {:noreply, socket}
+    end
+  end
+
+  @impl true
+  def handle_info(msg, socket) do
+    module = @page_modules[socket.assigns.live_action]
+
+    # Check if the module defines handle_info
+    if function_exported?(module, :handle_info, 2) do
+      case module.handle_info(msg, socket) do
+        :cont -> {:noreply, socket}
+        {:noreply, socket} -> {:noreply, socket}
+      end
+    else
+      {:noreply, socket}
+    end
+  end
+
+  @impl true
+  def render(assigns) do
+    # Cart page needs extra assigns computed at render time
+    assigns =
+      if assigns.live_action == :cart do
+        Pages.Cart.compute_assigns(assigns)
+      else
+        assigns
+      end
+
+    ~H"""
+    <BerrypodWeb.PageRenderer.render_page {assigns} />
+    """
+  end
+
+  # Clean up previous page state when transitioning
+  defp maybe_cleanup_previous_page(socket, :checkout_success) do
+    Pages.CheckoutSuccess.cleanup(socket)
+  end
+
+  defp maybe_cleanup_previous_page(socket, _), do: socket
+end