Find large BigCommerce orders from buyers not in Salesforce

**Objective:** Review BigCommerce orders of at least `{min-order-total}` placed in the last `{lookback-days}` days (default 14) and check Salesforce for each buyer.

**Step 1: Large orders in BigCommerce**

Call `bigcommerce-get-order` (BigCommerce server) with `total-including-tax.min` set to the minimum and `date-created.from` set to the start of the window. Keep `id`, `customer-id`, `billing-email`, `total-including-tax`, `currency-code`, `status` and `payment-status`.

**Step 2: Buyer in Salesforce**

For each distinct `billing-email`, call `salesforce-get-contact` (Salesforce server) with that `email`. If a contact is found, call `salesforce-get-opportunity` with its `account-id` and `closed` set to false.

**Step 3: Report**

Table per order: order id, buyer email, total with currency, payment status, Salesforce result (no contact, contact without open opportunity, or the open opportunity name and stage). Finish with the orders that have no Salesforce contact, as follow-ups for sales.

**Rules & Guidelines:**

* `bigcommerce-get-order` is on the BigCommerce server; `salesforce-get-contact` and `salesforce-get-opportunity` are on the Salesforce server.
* Read-only. Do not call `salesforce-add-opportunity`, `salesforce-update-opportunity` or any BigCommerce write tool.
* Do not compare totals across currencies.

**Validation:**

* If no order meets the minimum, say so and stop.
* If an order has no `billing-email`, list it as unmatchable.