feat: add Printify order submission and fulfilment tracking

Submit paid orders to Printify via provider API with idempotent
guards, Stripe address mapping, and error handling. Track fulfilment
status through submitted → processing → shipped → delivered via
webhook-driven updates (primary) and Oban Cron polling fallback.

- 9 fulfilment fields on orders (status, provider IDs, tracking, timestamps)
- OrderSubmissionWorker with retry logic, auto-enqueued after Stripe payment
- FulfilmentStatusWorker polls every 30 mins for missed webhook events
- Printify order webhook handlers (sent-to-production, shipment, delivered)
- Admin UI: fulfilment column in table, fulfilment card with tracking info,
  submit/retry and refresh buttons on order detail
- Mox provider mocking for test isolation (Provider.for_type configurable)
- 33 new tests (555 total), verified against real Printify API

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

lib/simpleshop_theme/orders/fulfilment_status_worker.ex

@@ -0,0 +1,46 @@
+defmodule SimpleshopTheme.Orders.FulfilmentStatusWorker do
+  @moduledoc """
+  Oban Cron worker that polls the fulfilment provider for status updates.
+
+  Runs every 30 minutes as a fallback for missed webhook events.
+  Only checks orders that are submitted or processing (i.e. awaiting
+  further status transitions).
+  """
+
+  use Oban.Worker, queue: :sync, max_attempts: 1
+
+  alias SimpleshopTheme.Orders
+
+  require Logger
+
+  @impl Oban.Worker
+  def perform(%Oban.Job{}) do
+    orders = Orders.list_submitted_orders()
+
+    if orders == [] do
+      :ok
+    else
+      Logger.info("Polling fulfilment status for #{length(orders)} order(s)")
+
+      Enum.each(orders, fn order ->
+        case Orders.refresh_fulfilment_status(order) do
+          {:ok, updated} ->
+            if updated.fulfilment_status != order.fulfilment_status do
+              Logger.info(
+                "Order #{order.order_number} status: #{order.fulfilment_status} → #{updated.fulfilment_status}"
+              )
+            end
+
+          {:error, reason} ->
+            Logger.warning(
+              "Failed to refresh status for order #{order.order_number}: #{inspect(reason)}"
+            )
+        end
+
+        Process.sleep(200)
+      end)
+
+      :ok
+    end
+  end
+end

lib/simpleshop_theme/orders/order.ex

@@ -6,6 +6,9 @@ defmodule SimpleshopTheme.Orders.Order do
   @foreign_key_type :binary_id
 
   @payment_statuses ~w(pending paid failed refunded)
+  @fulfilment_statuses ~w(unfulfilled submitted processing shipped delivered failed cancelled)
+
+  def fulfilment_statuses, do: @fulfilment_statuses
 
   schema "orders" do
     field :order_number, :string
@@ -19,6 +22,17 @@ defmodule SimpleshopTheme.Orders.Order do
     field :currency, :string, default: "gbp"
     field :metadata, :map, default: %{}
 
+    # Fulfilment
+    field :fulfilment_status, :string, default: "unfulfilled"
+    field :provider_order_id, :string
+    field :provider_status, :string
+    field :fulfilment_error, :string
+    field :tracking_number, :string
+    field :tracking_url, :string
+    field :submitted_at, :utc_datetime
+    field :shipped_at, :utc_datetime
+    field :delivered_at, :utc_datetime
+
     has_many :items, SimpleshopTheme.Orders.OrderItem
 
     timestamps(type: :utc_datetime)
@@ -45,4 +59,20 @@ defmodule SimpleshopTheme.Orders.Order do
     |> unique_constraint(:order_number)
     |> unique_constraint(:stripe_session_id)
   end
+
+  def fulfilment_changeset(order, attrs) do
+    order
+    |> cast(attrs, [
+      :fulfilment_status,
+      :provider_order_id,
+      :provider_status,
+      :fulfilment_error,
+      :tracking_number,
+      :tracking_url,
+      :submitted_at,
+      :shipped_at,
+      :delivered_at
+    ])
+    |> validate_inclusion(:fulfilment_status, @fulfilment_statuses)
+  end
 end

lib/simpleshop_theme/orders/order_submission_worker.ex

@@ -0,0 +1,56 @@
+defmodule SimpleshopTheme.Orders.OrderSubmissionWorker do
+  @moduledoc """
+  Oban worker for submitting paid orders to the fulfilment provider.
+
+  Enqueued after Stripe webhook confirms payment. Guards against
+  missing orders, unpaid orders, and already-submitted orders.
+  Retries up to 3 times with backoff for transient failures.
+  """
+
+  use Oban.Worker, queue: :checkout, max_attempts: 3
+
+  alias SimpleshopTheme.Orders
+
+  require Logger
+
+  @impl Oban.Worker
+  def perform(%Oban.Job{args: %{"order_id" => order_id}}) do
+    case Orders.get_order(order_id) do
+      nil ->
+        Logger.warning("Order submission: order #{order_id} not found")
+        {:cancel, :order_not_found}
+
+      %{payment_status: status} when status != "paid" ->
+        Logger.warning("Order submission: order #{order_id} not paid (#{status})")
+        {:cancel, :not_paid}
+
+      %{provider_order_id: pid} when not is_nil(pid) ->
+        Logger.info("Order submission: order #{order_id} already submitted")
+        :ok
+
+      %{shipping_address: addr} when addr == %{} or is_nil(addr) ->
+        Logger.warning("Order submission: order #{order_id} has no shipping address, will retry")
+        {:error, :no_shipping_address}
+
+      order ->
+        case Orders.submit_to_provider(order) do
+          {:ok, updated} ->
+            Logger.info(
+              "Order #{updated.order_number} submitted to provider (#{updated.provider_order_id})"
+            )
+
+            :ok
+
+          {:error, reason} ->
+            Logger.error("Order #{order.order_number} submission failed: #{inspect(reason)}")
+            {:error, reason}
+        end
+    end
+  end
+
+  def enqueue(order_id) do
+    %{order_id: order_id}
+    |> new()
+    |> Oban.insert()
+  end
+end