share provider connection logic between setup wizard and providers form

Extract Products.connect_provider/2 that tests the connection, fetches
shop_id, creates the record, and enqueues sync. Both the setup wizard
and the providers form now use this shared function instead of
duplicating the flow. Also makes the products empty state context-aware
(distinguishes "no provider" from "provider connected but no products").

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

lib/berrypod_web/live/admin/providers/form.ex

@@ -82,23 +82,18 @@ defmodule BerrypodWeb.Admin.Providers.Form do
   end
 
   defp save_connection(socket, :new, params) do
+    api_key = params["api_key"] || socket.assigns[:pending_api_key]
     provider_type = socket.assigns.provider_type
 
-    params =
-      params
-      |> Map.put("provider_type", provider_type)
-      |> maybe_add_config(provider_type, socket.assigns.test_result)
-      |> maybe_add_name(provider_type, socket.assigns.test_result)
-
-    case Products.create_provider_connection(params) do
+    case Products.connect_provider(api_key, provider_type) do
       {:ok, _connection} ->
         {:noreply,
          socket
          |> put_flash(:info, "Connected to #{socket.assigns.provider.name}!")
          |> push_navigate(to: ~p"/admin/settings")}
 
-      {:error, %Ecto.Changeset{} = changeset} ->
-        {:noreply, assign(socket, form: to_form(changeset))}
+      {:error, _reason} ->
+        {:noreply, put_flash(socket, :error, "Could not connect — check your API key")}
     end
   end
 
@@ -115,32 +110,6 @@ defmodule BerrypodWeb.Admin.Providers.Form do
     end
   end
 
-  # Printify returns shop_id, Printful returns store_id
-  defp maybe_add_config(params, "printify", {:ok, %{shop_id: shop_id}}) do
-    config = Map.get(params, "config", %{}) |> Map.put("shop_id", to_string(shop_id))
-    Map.put(params, "config", config)
-  end
-
-  defp maybe_add_config(params, "printful", {:ok, %{store_id: store_id}}) do
-    config = Map.get(params, "config", %{}) |> Map.put("store_id", to_string(store_id))
-    Map.put(params, "config", config)
-  end
-
-  defp maybe_add_config(params, _type, _result), do: params
-
-  defp maybe_add_name(params, "printify", {:ok, %{shop_name: name}}) when is_binary(name) do
-    Map.put_new(params, "name", name)
-  end
-
-  defp maybe_add_name(params, "printful", {:ok, %{store_name: name}}) when is_binary(name) do
-    Map.put_new(params, "name", name)
-  end
-
-  defp maybe_add_name(params, type, _result) do
-    provider = Provider.get(type)
-    Map.put_new(params, "name", (provider && provider.name) || type)
-  end
-
   defp encrypt_api_key(api_key) do
     case Berrypod.Vault.encrypt(api_key) do
       {:ok, encrypted} -> encrypted