fix(invoice): detect pickup via missing shippingAddress (real signal for built-in 'Shop location' rate)

Reproduced against real dev order #1032: the built-in 'Shop location'
shipping rate sets neither a pickup keyword nor deliveryCategory:

  shippingLine: { title: 'Shop location', code: 'Shop location',
                  source: 'shopify', deliveryCategory: null }
  shippingAddress: null
  requiresShipping: true

So neither v2 (string regex on title/code) nor v3 (deliveryCategory)
caught it. The robust signal is 'requiresShipping && shippingAddress
== null': Shopify rejects checkout for a normal shipping order without
an address, so this combination is conclusive proof of pickup.

- Query Order.requiresShipping (only needs read_orders).
- detectPickup() now treats missing-address-but-requires-shipping as the
  primary signal; deliveryCategory + title/code regex remain as
  fallbacks for Local-Pickup-app installs and custom rates.
- New fixture buildShopLocationPickupOrder() in render-sample.ts
  mirrors order #1032 exactly so we never regress on this shape.

app/services/invoice/loadOrderForInvoice.server.ts

@@ -13,6 +13,11 @@ export interface RawOrderForInvoice {
   currencyCode: string;
   displayFinancialStatus: string | null;
   paymentGatewayNames: string[];
+  /** True when the order contains at least one shippable line item. For
+   *  pickup orders this is `true` but `shippingAddress` is `null` — that
+   *  combination is the most reliable pickup signal we have without
+   *  hitting `read_merchant_managed_fulfillment_orders`. */
+  requiresShipping: boolean;
   customer: {
     firstName: string | null;
     lastName: string | null;
@@ -118,6 +123,7 @@ const QUERY = `#graphql
       displayFinancialStatus
       paymentGatewayNames
       taxesIncluded
+      requiresShipping
       customer {
         firstName
         lastName
@@ -229,6 +235,7 @@ interface RawAdminResponse {
       displayFinancialStatus: string | null;
       paymentGatewayNames: string[] | null;
       taxesIncluded: boolean;
+      requiresShipping: boolean | null;
       customer: {
         firstName: string | null;
         lastName: string | null;
@@ -286,6 +293,7 @@ export async function loadOrderForInvoice(
     displayFinancialStatus: order.displayFinancialStatus,
     paymentGatewayNames: order.paymentGatewayNames ?? [],
     taxesIncluded: order.taxesIncluded,
+    requiresShipping: order.requiresShipping ?? false,
     customer: order.customer,
     billingAddress: order.billingAddress,
     shippingAddress: order.shippingAddress,