Find Chargebee payments that are not recorded in Rillet

**Objective:** For Chargebee customer `{chargebee-customer-id}`, check that each successful payment on or after {date-from} (default: the last 60 days) is recorded as an invoice payment in Rillet.

**Step 1: Read Chargebee payments (chargebee server)**

Call `chargebee-get-transaction` with `customer-id` = {chargebee-customer-id}, `type` set to payment, `status` set to success, and `date.from` = {date-from}. Keep `id`, `date`, `amount`, `currency-code`, `payment-method`, `gateway` and `subscription-id`. Also call `chargebee-get-customer` with `id` = {chargebee-customer-id} for the `email`.

**Step 2: Find the Rillet customer and its invoices (rillet server)**

Call `rillet-get-customer-emails` and match `email` to the Chargebee email to get the Rillet `customer-id`. Call `rillet-get-invoices` and keep that customer's invoices (`invoice-id`, `invoice-number`, `total`, `amount-due`).

**Step 3: Read Rillet payments (rillet server)**

Call `rillet-get-invoice-payments` (no filters) and keep rows whose `invoice-id` belongs to one of that customer's invoices. Keep `payment-id`, `date`, `amount`, `currency`, `status`.

**Step 4: Match**

Match each Chargebee payment to a Rillet payment with the same amount and currency and a date within 3 days. Each Rillet payment can match only one Chargebee payment.

**Step 5: Report**

List Chargebee payments with no Rillet payment (these are unrecorded cash), Rillet payments with no Chargebee payment, and matched pairs. End with the total unrecorded amount per currency.

**Rules & Guidelines:**

* `chargebee-get-transaction` and `chargebee-get-customer` are on the chargebee server. `rillet-get-customer-emails`, `rillet-get-invoices` and `rillet-get-invoice-payments` are on the rillet server.
* Read-only. Do not call `rillet-add-invoice-payment` or `rillet-update-invoice-payment`; recommend the entry in the report instead.

**Validation:**

* If the customer is not found in Rillet, report that and stop.
* If Chargebee has no payments in the window, say so and stop.
* If the same amount appears more than once on one side, flag the match as ambiguous.