Find BigCommerce stock levels that differ from Dynamics GP

**Objective:** Find BigCommerce products whose `inventory-level` differs from the Dynamics GP available quantity by at least `{min-difference}` units (default 1), limited to the SKU `{sku-filter}` when given, checking at most `{max-products}` products (default 50).

**Step 1: List BigCommerce products**

Call `bigcommerce-get-product` (bigcommerce server) with `max-records` set to the product limit and, when `{sku-filter}` is given, `sku` set to it. Keep `id`, `sku`, `name` and `inventory-level`. Skip products with no `sku`.

**Step 2: Look each SKU up in Dynamics GP**

For each SKU call `dynamics-gp-get-iv-item-quantity` (dynamics-gp server) with `item-number` set to the SKU. Sum `quantity-on-hand` across rows and subtract `quantity-allocated`. If no row comes back, record the SKU as not in Dynamics GP and continue.

**Step 3: Report**

Three lists. Mismatches: SKU, name, BigCommerce level, GP available, difference, sorted by absolute difference descending. Not in Dynamics GP: SKUs only. Summary counts: products checked, matched, mismatched, missing from GP.

**Rules & Guidelines:**

* `bigcommerce-*` tools run on the bigcommerce server and `dynamics-gp-*` tools on the dynamics-gp server. Both servers must be connected.
* Where a GP tool takes `company`, pass `{gp-company}` when it is given; if it is empty, omit `company`.
* This prompt is read-only. Never call any `bigcommerce-*-add`, `-update` or `-delete` tool, and never call any `dynamics-gp-*-add`, `-update` or `-note` tool.

**Validation:**

* If BigCommerce returns no products, say so and stop.
* Say how many products were checked, since the list stops at the product limit.