add pagination across all admin and shop views

URL-based offset pagination with ?page=N for bookmarkable pages.
Admin views use push_patch, shop collection uses navigate links.
Responsive on mobile with horizontal-scroll tables and stacking
pagination controls. Includes dev seed script for testing.

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

lib/berrypod_web/components/shop_components/product.ex

@@ -1714,4 +1714,84 @@ defmodule BerrypodWeb.ShopComponents.Product do
     </div>
     """
   end
+
+  # ── Shop pagination ────────────────────────────────────────────
+
+  @doc """
+  Renders pagination controls for the shop collection page.
+
+  Uses URL navigation (`<.link navigate=...>`) so pages are bookmarkable.
+
+  ## Attributes
+
+    * `page` - Required. A `%Berrypod.Pagination{}` struct.
+    * `base_path` - Required. The base URL path (e.g. "/collections/all").
+    * `params` - Extra query params to preserve (e.g. %{"sort" => "newest"}).
+  """
+  attr :page, Berrypod.Pagination, required: true
+  attr :base_path, :string, required: true
+  attr :params, :map, default: %{}
+
+  def shop_pagination(assigns) do
+    assigns =
+      assigns
+      |> assign(:showing, Berrypod.Pagination.showing_text(assigns.page))
+      |> assign(:numbers, Berrypod.Pagination.page_numbers(assigns.page))
+
+    ~H"""
+    <nav
+      :if={@page.total_pages > 1}
+      aria-label="Pagination"
+      class="shop-pagination"
+    >
+      <p class="shop-pagination-showing">{@showing}</p>
+
+      <div class="shop-pagination-buttons">
+        <.link
+          :if={@page.page > 1}
+          navigate={pagination_url(@base_path, @page.page - 1, @params)}
+          class="shop-pagination-btn"
+          aria-label="Previous page"
+        >
+          &lsaquo; Prev
+        </.link>
+
+        <%= for item <- @numbers do %>
+          <%= case item do %>
+            <% :ellipsis -> %>
+              <span class="shop-pagination-ellipsis" aria-hidden="true">&hellip;</span>
+            <% n -> %>
+              <.link
+                navigate={pagination_url(@base_path, n, @params)}
+                aria-label={"Page #{n}"}
+                aria-current={n == @page.page && "page"}
+                class={["shop-pagination-btn", n == @page.page && "shop-pagination-btn-active"]}
+              >
+                {n}
+              </.link>
+          <% end %>
+        <% end %>
+
+        <.link
+          :if={@page.page < @page.total_pages}
+          navigate={pagination_url(@base_path, @page.page + 1, @params)}
+          class="shop-pagination-btn"
+          aria-label="Next page"
+        >
+          Next &rsaquo;
+        </.link>
+      </div>
+    </nav>
+    """
+  end
+
+  defp pagination_url(base_path, page, params) do
+    query = if page > 1, do: Map.put(params, "page", to_string(page)), else: params
+
+    if query == %{} do
+      base_path
+    else
+      base_path <> "?" <> URI.encode_query(query)
+    end
+  end
 end