Find orders billed but not shipped, or shipped but not billed

**Objective:** Reconcile FreshBooks invoices created since `{since-date}` against ShipStation shipments shipped since the same date, and report orders that are billed but not shipped or shipped but not billed. If `{since-date}` is empty, use the last 30 days.

**Step 1: Read invoices (FreshBooks server)**

Call `freshbooks-get-invoice` with create-date.from set to `{since-date}`. Keep `invoice-number`, `po-number`, `customer-id`, `organization`, `amount`, `payment-status` and `status-name`. Ignore invoices whose status-name is draft.

**Step 2: Read shipments (ShipStation server)**

Call `shipstation-get-shipment` with ship-date.from set to `{since-date}`. Keep `shipment-number`, `external-order-id`, `ship-to-name`, `shipment-status` and `ship-date`.

**Step 3: Match**

Match an invoice to a shipment when the shipment's external-order-id equals the invoice's invoice-number or po-number (ignore case and leading zeros). If that finds nothing for an invoice, fall back to ship-to-name equal to the invoice's organization and say the match is weak.

**Step 4: Report**

Three tables: billed and paid but no shipment found, shipped but no invoice found, and matched pairs where the shipment is cancelled or voided. Finish with counts for each.

**Rules & Guidelines:**

* `freshbooks-get-invoice` is on the freshbooks server; `shipstation-get-shipment` is on the shipstation server.
* This prompt is read-only. Do not call any freshbooks add, update, delete, mark or send tool.
* Many invoices will not be physical orders (services); say that in the report rather than treating each as an error.

**Validation:**

* If either server returns no records, say so and stop.
* If external-order-id values do not look like invoice numbers at all, report that the two systems use different order references and show three examples from each side.