Move stock between sites only when it is really there

**Objective:** Move `{quantity}` units of item `{item-number}` from site `{from-site}` to site `{to-site}` with an inventory transfer, after checking the stock is there and the user has confirmed.

**Step 1: Gather what the write needs**

Before any call, ask the user for: the company (if more than one is in use), the batch number to put the transfer in, and the transfer document number. Use today as the document date unless they give one. Pass the company as `company` on every call.

**Step 2: Check both sites**

Call `dynamics-gp-get-iv-site` with `site-id` set to `{from-site}` and again for `{to-site}`. Stop if either does not exist or is `inactive`, or if they are the same site.

**Step 3: Check stock**

Call `dynamics-gp-get-iv-item-quantity` with `item-number` set to `{item-number}`. Find the site-level row for `{from-site}` (by `record-type` and the site code in `location-code-from-item-master`). Available = `quantity-on-hand` minus `quantity-allocated`. If available is less than `{quantity}`, stop and report the shortfall. If you cannot identify the site row with confidence, show the rows you found and ask the user to confirm the available quantity before continuing.

**Step 4: Confirm**

Show: item, description, quantity, from site, to site, available at the source before and after, batch number, document number, document date, company. Ask for explicit confirmation. Do nothing further without a clear yes.

**Step 5: Write**

1. Call `dynamics-gp-iv-inventory-transfer-add` once with `document-number`, `document-date`, `batch-number` and `company`. Do not set `post-to-g-l` unless the user asked for it.
2. Only if that succeeded, call `dynamics-gp-iv-inventory-transfer-add-line` once with `document-number`, `item-number`, `transfer-from-location` = `{from-site}`, `transfer-to-location` = `{to-site}` and `transaction-quantity` = `{quantity}`.

If the line fails after the header succeeded, tell the user plainly that an empty transfer document now exists under that number and needs removing or completing in Dynamics GP. Do not retry either call automatically.

**Step 6: Verify**

Call `dynamics-gp-get-iv-inventory-transaction` with `document-number` and report what was stored: type, status, item, quantity, locations.

**Rules & Guidelines:**

* The only write tools this prompt may call are `dynamics-gp-iv-inventory-transfer-add` and `dynamics-gp-iv-inventory-transfer-add-line`, once each, after Step 4.
* Do not call `dynamics-gp-iv-item-add`, `dynamics-gp-pm-purchase-order-add` or any other write tool, even to fix a problem you find.

**Validation:**

* If `{quantity}` is not a positive number, stop and ask for a valid quantity.
* If the item does not exist, stop and say so.