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/contact_notifier.ex

@@ -0,0 +1,61 @@
+defmodule Berrypod.ContactNotifier do
+  @moduledoc """
+  Sends contact form submissions to the shop owner.
+  """
+
+  import Swoosh.Email
+
+  alias Berrypod.{Mailer, Settings}
+
+  require Logger
+
+  @doc """
+  Delivers a contact form message to the shop owner's email.
+
+  Expects a map with "name", "email", and "message" keys (string keys,
+  as received from form params). "subject" is optional.
+  """
+  def deliver_contact_message(%{"name" => name, "email" => email, "message" => message} = params)
+      when is_binary(name) and name != "" and is_binary(email) and email != "" and
+             is_binary(message) and message != "" do
+    subject =
+      if params["subject"] in [nil, ""], do: "Contact form message", else: params["subject"]
+
+    shop_name = Settings.get_setting("shop_name", "Berrypod")
+    from_address = Settings.get_setting("email_from_address", "contact@example.com")
+    to_address = Settings.get_setting("contact_email") || from_address
+
+    body = """
+    ==============================
+
+    New message from your #{shop_name} contact form
+
+    Name: #{name}
+    Email: #{email}
+    Subject: #{subject}
+
+    #{message}
+
+    ==============================
+    """
+
+    email_msg =
+      new()
+      |> to(to_address)
+      |> from({shop_name, from_address})
+      |> reply_to(email)
+      |> subject("[#{shop_name}] #{subject}")
+      |> text_body(body)
+
+    case Mailer.deliver(email_msg) do
+      {:ok, _metadata} = result ->
+        result
+
+      {:error, reason} = error ->
+        Logger.warning("Failed to send contact form email: #{inspect(reason)}")
+        error
+    end
+  end
+
+  def deliver_contact_message(_), do: {:error, :invalid_params}
+end