Find out why late Shopify orders are stuck

**Objective:** Find the fulfillment orders that have been waiting more than `{older-than-days}` days (default 3), work out why each is stuck, and group them by location. Location filter: `{location-name}` (default all locations).

**Step 1: Pull the backlog**

Call `shopify-get-fulfillment-order` filtered by `order-processed-at.to` (today minus the threshold) once for each open-type status the tool's schema lists: open, in progress, on hold, and incomplete. If `{location-name}` is given, also filter by `assigned-location-name.contains`. Keep fulfillment-order-id, order-id, order-number, status, request-status, assigned-location-name, delivery-method-type, fulfill-by and order-processed-at.

**Step 2: Find the reason for each**

* On hold: call `shopify-get-fulfillment-order-hold` filtered by `fulfillment-order-id` for reason, display-reason and held-by-app-title.
* Sent to a fulfillment service (request-status is not unsubmitted): call `shopify-get-fulfillment-order-merchant-request` filtered by `fulfillment-order-id` to see what was sent and when, and whether it was accepted or rejected.
* Otherwise: call `shopify-get-fulfillment-order-line` filtered by `fulfillment-order-id` for the items and remaining-quantity. Where you have many, check stock for the worst few: call `shopify-get-inventory-level` filtered by `inventory-item-id` and see whether available is zero or below at the assigned location.
* Past its fulfill-by date: mark as overdue regardless of reason.

**Step 3: Report**

Grouped by assigned location, each group sorted oldest first:

| Order | Processed | Days waiting | Status | Fulfill by | Blocker | Detail |

Blocker is one of: on hold, awaiting fulfillment service, out of stock, overdue, no obvious blocker. Close with totals per location and per blocker, and the three changes that would clear the most orders.

**Rules & Guidelines:**

* This prompt is read-only. Do not call `shopify-update-order`, `shopify-add-inventory-level`, `shopify-update-location` or any other add or update tool.
* Only say out of stock when the inventory level read shows it. Otherwise say no obvious blocker.
* Cap the stock checks at 20 items; say when you stopped.

**Validation:**

* If no fulfillment orders match, say the backlog is clear at that threshold and stop.
* If `{location-name}` matches no fulfillment orders, call `shopify-get-location` filtered by `name.contains` and list the location names that do exist.