Rank BigCommerce products by units sold and find slow movers

**Objective:** Rank products by units sold, showing the top `{top-n}` (default 10) and the slow movers, optionally for brand `{brand-name}`.

**Step 1: Resolve the brand (optional)**

If a brand name was given, call `bigcommerce-get-brand` with `name`; if it matches several, list them and stop. Use the brand's `id` as `brand-id` below.

**Step 2: Best sellers**

Call `bigcommerce-get-product` with `visible` set to true, `total-sold.min` of 1, and `brand-id` if resolved. Sort by `total-sold` yourself.

**Step 3: Slow movers**

Call `bigcommerce-get-product` with `visible` set to true, `date-created.to` set to 90 days ago, and `brand-id` if resolved. Keep those whose `total-sold` is 0.

**Step 4: Report**

Top table: name, sku, price, stock, total sold. Slow movers table: name, sku, price, stock, date created. Finish with two or three observations (for example high stock with no sales).

**Rules & Guidelines:**

* This is a read-only job. Never call any `bigcommerce-*-add`, `bigcommerce-*-update` or `bigcommerce-*-delete` tool. Do not suggest that you changed anything.
* Rank only on `total-sold`; do not estimate revenue from it unless you show the price used.

**Validation:**

* If a read returns no records, say so plainly and stop; do not invent figures.
* If a result hits the maximum records limit, say the figures may be incomplete and name the filter that would narrow it.