add no-JS contact form and noscript banner

Wire up the contact form with action/method/name attrs so it works
without JavaScript. Add ContactNotifier, ContactController, and a
noscript info banner in the shop root layout.

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

lib/berrypod_web/controllers/contact_controller.ex

@@ -0,0 +1,27 @@
+defmodule BerrypodWeb.ContactController do
+  use BerrypodWeb, :controller
+
+  alias Berrypod.ContactNotifier
+
+  @doc """
+  Handles contact form submission (no-JS fallback).
+  """
+  def create(conn, params) do
+    case ContactNotifier.deliver_contact_message(params) do
+      {:ok, _} ->
+        conn
+        |> put_flash(:info, "Message sent! We'll get back to you soon.")
+        |> redirect(to: ~p"/contact")
+
+      {:error, :invalid_params} ->
+        conn
+        |> put_flash(:error, "Please fill in all required fields.")
+        |> redirect(to: ~p"/contact")
+
+      {:error, _} ->
+        conn
+        |> put_flash(:error, "Sorry, something went wrong. Please try again.")
+        |> redirect(to: ~p"/contact")
+    end
+  end
+end