See which Chargebee dunning customers Business Central still serves

**Objective:** List Chargebee invoices in dunning that are due before `{due-before}` and, for each customer, show whether Business Central already treats them as a credit risk.

**Step 1: Chargebee dunning invoices**

Call `chargebee-get-invoice` (Chargebee server) with `status` set to payment_due, `due-date.to` set to `{due-before}` and `max-records` 50. Keep rows whose `dunning-status` is not empty. Group by `customer-id` and add up `amount-due`. If nothing is in dunning, report that and stop.

**Step 2: Customer details**

For each customer, call `chargebee-get-customer` (Chargebee server) with `id` and keep `email`, `company` and `auto-collection`.

**Step 3: Business Central position**

Call `business-central-get-customer` (Business Central server) with `email`. Keep `customer-number`, `balance-due`, `credit-limit`, `blocked`. Call `business-central-get-reminder` (Business Central server) with `customer-number` and keep the highest `reminder-level`. If the customer is not found, flag "not in Business Central".

**Step 4: Report**

Rank customers by Chargebee amount due. For each show: Chargebee amount due, oldest due date, dunning status, Business Central balance due, credit limit, blocked flag, highest reminder level, and a risk note: "Already blocked", "Over credit limit", "No reminder raised in Business Central" or "Not in Business Central".

**Rules & Guidelines:**

* `chargebee-get-invoice` and `chargebee-get-customer` are on the Chargebee server; `business-central-get-customer` and `business-central-get-reminder` are on the Business Central server.
* Read-only. Do not call `business-central-update-customer` to block anyone; recommend it instead.

**Validation:**

* If `{due-before}` is empty, use today's date.
* Do not compare balances across different currencies.