Match Chargebee invoices to PowerGP Online sales documents

**Objective:** Match Chargebee invoices from the last {lookback-days} days (default 60) with the PowerGP sales documents that billed the same work, using the purchase order number, for {customer} if given.

**Step 1: Chargebee invoices**

Call `chargebee-get-invoice` (chargebee) with `date.from` set to the lookback start and `customer-id` if the customer was resolved with `chargebee-get-customer` (`company.contains`). Keep invoices that have `po-number`. Record `id`, `po-number`, `total`, `date`, `status`.

**Step 2: PowerGP documents**

Call `powergp-online-get-salesdocuments` (powergp-online-ai) with `document-date.from` set to the lookback start, and `customer-name.contains` if a customer was given. Match each invoice to a document whose `customer-po` equals `po-number` (ignore case and spaces). If you need the lines, call `powergp-online-get-salestransactions` with the matched `document-number`.

**Step 3: Report**

Table of invoice id, po-number, Chargebee total, PowerGP document-number and document-amount, and the difference. List invoices with no PO number, and PO numbers with no PowerGP document.

**Rules & Guidelines:**

* Tools prefixed powergp-online- belong to the powergp-online-ai server; tools prefixed chargebee- belong to the chargebee server. Both servers must be connected.
* Read-only: call only the get tools named above. Never create, change or delete anything in either system.
* Never print card or bank details; report ids, names and amounts only.

**Validation:**

* If no invoice has a PO number, say so and stop.
* If several PowerGP documents share a PO, show them all and compare the sum.