Find customers who owe money but cannot be emailed

**Objective:** List contacts who unsubscribed or bounced in Constant Contact since {since-date} and who owe money in NetSuite, so collections knows email will not reach them.

**Step 1: Read email failures**

Call `constant-contact-get-campaign-unsubscribe` with `created-date.from` = {since-date}, and `constant-contact-get-campaign-bounce` with the same `created-date.from`. Collect the email addresses and the reason or bounce-type.

**Step 2: Match to NetSuite**

For each email (cap at 40) call `netsuite-get-customer` with `email`. Skip emails that are not customers.

**Step 3: Check what they owe**

For each matched customer call `netsuite-get-invoice` with `customer-id` and `unpaid-amount.min` = {min-unpaid} (default 0.01). Total the unpaid amounts and note the oldest invoice date.

**Step 4: Report**

A table sorted by amount owed: customer, email, unsubscribed or bounced, reason, unpaid total, oldest unpaid invoice. Recommend a non-email channel for each.

**Rules & Guidelines:**

* `netsuite-*` tools are on the netsuite server; `constant-contact-*` tools are on the constant-contact server. Both servers must be connected.
* This prompt is read-only. Never call any `netsuite-add-*` or `netsuite-update-*` tool, and never call `constant-contact-add-*`, `constant-contact-update-*` or `constant-contact-resend-campaign-to-non-openers`.
* Match the two systems on email address, case-insensitive. If a record has no email, report it as unmatched and continue.

**Validation:**

* If no unsubscribes or bounces exist, say so and stop.
* If a customer owes nothing, leave them out and count them.