Check whether a 2Checkout order was invoiced and paid in Intacct

**Objective:** Trace the 2Checkout order for `{billing-last-name}` (optionally narrowed by `{order-reference}`, the 2Checkout external reference) into Intacct and report whether it was invoiced and paid.

**Step 1: Find the order in 2Checkout**

Call `2checkout-get-order` (2Checkout server) with `billing-last-name`, and `external-reference` when `{order-reference}` is given. If more than one order matches, list them (reference-number, order-date, status, gross-discounted-price, currency) and stop to ask which one. Keep `reference-number`, `gross-discounted-price`, `currency`, `order-date` and `status`.

**Step 2: Find the customer and invoice in Intacct**

Call `intacct-get-customer` (Intacct server) with `customer-name.contains` set to the billing last name and note the `customer-id`. Then call `intacct-get-invoice` with that `customer-id`, `invoice-date.from` 7 days before the order date and `invoice-date.to` 60 days after. Prefer the invoice whose `reference-number` contains the 2Checkout reference-number, otherwise whose `total-amount` equals the order amount.

**Step 3: Find the payment**

Call `intacct-get-ar-payment` with the same `customer-id`, `receipt-date.from` set to the order date, and amount filters around the order amount. Note `total-paid`, `date-fully-paid` and `state` on the invoice.

**Step 4: Report**

Order summary, matched customer, matched invoice (number, amount, `total-due`), matched payment (date, amount, method), and a verdict: Paid, Invoiced and unpaid, Not invoiced, or Customer not found in Intacct.

**Rules & Guidelines:**

* `2checkout-get-order` is on the 2Checkout server; `intacct-get-customer`, `intacct-get-invoice` and `intacct-get-ar-payment` are on the Intacct server.
* Read-only. Do not call `2checkout-order-refund`, `2checkout-order-cancel`, `intacct-create-order-entry-document` or any other write tool.

**Validation:**

* If no 2Checkout order matches, say so and stop.
* If no Intacct customer matches, report Customer not found in Intacct and stop; do not guess a customer.
* If currencies differ between order and invoice, report both and flag it.