Match a 2Checkout order to its NetSuite invoice

**Objective:** Trace 2Checkout order `{reference-number}` to its NetSuite invoice or cash sale, looking back `{lookback-days}` days (default 30).

**Step 1: Find the order (2checkout server)**

Call `2checkout-get-order` and find the record whose `reference-number` is `{reference-number}` (use `external-reference` or the billing name filters to narrow the search, with a small `max-records`). Note `order-date`, `gross-discounted-price`, `currency`, `external-reference`, `billing-first-name` and `billing-last-name`. If no order matches, stop.

**Step 2: Find the NetSuite customer (netsuite server)**

Call `netsuite-get-customer` with `name.contains` set to the billing last name. If several match, list them and ask the user to choose. Note `internal-id`.

**Step 3: Find the financial document (netsuite server)**

Call `netsuite-get-invoice` with `customer-id` = that `internal-id` and `date.from` = order date minus `{lookback-days}` days. If `external-reference` is set, also try `document-number` = `external-reference`. If no invoice fits, call `netsuite-get-cashsale` with `customer-first-name` and the same date range.

**Step 4: Report**

State: order found, customer found, document found (document number, date, total) and whether the total equals `gross-discounted-price` in the same currency. Say clearly when no document exists.

**Rules & Guidelines:**

* `2checkout-get-order` is on the 2checkout server; `netsuite-get-customer`, `netsuite-get-invoice` and `netsuite-get-cashsale` are on the netsuite server.
* Read-only: do not call any 2checkout action tool (for example `2checkout-order-refund`, `2checkout-customer-update`, `2checkout-customer-add`) and do not call any netsuite add or update tool (for example `netsuite-add-customer`, `netsuite-update-customer`, `netsuite-add-invoice`).

**Validation:**

* If a total differs, report both values and the difference; do not call it a match.
* If the currency differs, report it and do not convert.