Find top BigCommerce customers without open Pipedrive deals

**Objective:** Find the top `{top-n}` BigCommerce customers by spend over the last `{lookback-days}` days (default 90, top 10) who have no open deal in Pipedrive.

**Step 1: Read recent orders**

Call `bigcommerce-get-order` with `date-created.from` set to today minus `{lookback-days}` days and `max-records` 250. Group by `customer-id`, summing `total-including-tax` and subtracting `refunded-amount`. Ignore customer-id 0 (guest orders). Take the top `{top-n}`.

**Step 2: Identify them**

For each, call `bigcommerce-get-customer` with `id` set to the `customer-id` to get `name`, `email` and `company`.

**Step 3: Look for a CRM deal**

Call `pipedrive-get-person` with `email` set to the customer `email`. If found, read `open-deals`; if it is above zero, confirm with `pipedrive-get-deal` using `organization-id` set to the person `organization-id` and `status` set to open. If the person is missing, or has no open deals, flag the customer.

**Step 4: Report**

Report the flagged customers ranked by net spend: name, company, net spend, order count, last order date, and whether the cause is "no CRM person" or "no open deal". Also list the top customers who do have an open deal, briefly.

**Rules & Guidelines:**

* `bigcommerce-*` tools are on the bigcommerce server and `pipedrive-*` tools are on the pipedrive server. Both servers must be connected.
* This is read-only. Never call any add, update or delete tool on either server (for example `bigcommerce-customer-update`, `bigcommerce-customer-add`, `pipedrive-add-person`, `pipedrive-update-deal`, `pipedrive-add-activity`).

**Validation:**

* If the 250 order cap was reached, say the ranking may be incomplete.
* If no orders exist in the period, say so and stop.