Stop promoting to clients who owe you money

**Objective:** Find clients whose FreshBooks invoices are overdue by more than `{min-outstanding}` (default 0) and who are still receiving Drip campaigns, so marketing does not promote to someone who owes money. Check up to `{max-invoices}` invoices (default 50).

**Step 1: Find overdue invoices in FreshBooks**

Call `freshbooks-get-invoice` (FreshBooks server) with `due-date.to` set to today, `outstanding.min` set to `{min-outstanding}` (use 0.01 if that is 0) and `max-records` set to `{max-invoices}`. Group the results by `customer-id` and total the outstanding amount per client.

**Step 2: Get each client's email**

For each `customer-id`, call `freshbooks-get-client` with it as `id` to get the `email`. Skip clients with no email and list them in the report.

**Step 3: Check Drip**

For each email, call `drip-get-campaign-subscriber` (Drip server) with `email` set to it. Keep rows whose `campaign-status` and subscriber `status` are both active.

**Step 4: Report**

Table of clients to review: name, organization, email, overdue total, oldest due date, and the campaigns they are active in. End with counts of overdue clients, clients with no email, clients not in Drip, and clients active in campaigns.

**Rules & Guidelines:**

* `freshbooks-get-invoice` and `freshbooks-get-client` are on the FreshBooks server. `drip-get-campaign-subscriber` is on the Drip server.
* Read-only. Do not call `drip-pause-campaign`, `drip-remove-subscriber-from-campaign`, `drip-remove-subscriber-from-all-campaigns`, `drip-add-subscriber-tag`, `freshbooks-send-invoice-by-email` or any other write tool. Recommend the follow-up prompt that acts on a single client instead.
* Both servers take a `company` parameter; pass the company the user is authorized for on every call, and never mix companies.

**Validation:**

* If there are no overdue invoices, say so and stop.
* Match clients to subscribers on email only.
* If the invoice list hit the `{max-invoices}` limit, say the result may be incomplete.