Refund a WooCommerce order by the right route and amount

**Objective:** Refund `{amount}` (default: everything still refundable) on order `{order-number}`, for the reason `{reason}`, through the right route for its payment method.

**Step 1: Find the order and what has already been refunded**

* `woocommerce-get-order` with `order-number` = `{order-number}`. Keep `order-id`, `status`, `total`, `currency`, `paid-date` and `payment-method-name`. If nothing matches, or more than one does, say so and stop.
* `woocommerce-get-refund` with `order-id`. Already refunded = the sum of the absolute `amount` values.
* `woocommerce-get-order-line` with `order-id`, to show what was bought.

Remaining refundable = `total` minus already refunded.

**Step 2: Check the refund**

* Status `pending`, `failed` or `cancelled` with no `paid-date`: nothing was paid. Refuse and stop.
* Remaining refundable is 0: say it is fully refunded and stop.
* `{amount}` empty: refund the full remaining amount. `{amount}` above the remaining amount, 0 or negative: stop and give the remaining amount.
* Route: pass `refund-via-gateway` false when `payment-method-name` is a manual method (Direct bank transfer, Check payments, Cash on delivery) or empty; the money must then be returned outside WooCommerce, and you must say so. Otherwise pass true.

**Step 3: Confirm**

Show: order number, customer, order total, already refunded, amount to refund now, currency, route (gateway or manual), reason. Point out that this tool refunds an amount, not line items, so stock is not restored; if the goods come back, the user can restock with the update-product-by-sku prompt. Wait for an explicit yes.

**Step 4: Refund**

Call `woocommerce-add-refund` once with `order-id`, `amount`, `reason` = `{reason}` and `refund-via-gateway`.

**Step 5: Verify and report**

Call `woocommerce-get-refund` with `order-id` and `woocommerce-get-order` with `order-id`. Report the refund id, amount, whether `refunded-payment` shows the gateway returned it, the new order status (a full refund moves the order to `refunded` on its own), and the amount still refundable.

**Rules & Guidelines:**

* The only write tool this prompt may call is `woocommerce-add-refund`, once.
* Do not call any other write tool (`woocommerce-add-order`, `woocommerce-update-order`, `woocommerce-add-order-note`, `woocommerce-send-order-details`, `woocommerce-add-customer`, `woocommerce-update-customer`, `woocommerce-add-product`, `woocommerce-update-product`, `woocommerce-update-product-variation`, `woocommerce-add-coupon`, `woocommerce-update-coupon`). In particular never set the status to `refunded` with `woocommerce-update-order`.
* If a gateway refund fails, report the gateway's error and stop. Never retry it as a manual refund without the user asking, because the customer would get nothing back.

**Validation:**

* If `{reason}` is empty, ask for one before refunding; it is shown on the order.
* If the user's confirmation is anything other than a clear yes, stop without writing.