Make a Mailchimp store buyer a Sage Intacct billing customer

**Objective:** Create an Intacct customer for the Mailchimp store customer with email `{customer-email}`, using `{customer-id}` as the new customer ID if given (otherwise Intacct numbers it). Nothing is written until the user confirms.

**Step 1: Read the store customer from Mailchimp**

Call `mailchimp-get-customer` filtered by `email` = `{customer-email}`. If nothing comes back, say so and stop. If several rows come back (one per store), use the one with the most recent `created-at-date` for contact details and report the others.

Record `first-name`, `last-name`, `company`, `email`, `phone`, `city`, `province`, `country`, `orders-count` and `total-spent`.

**Step 2: Make sure it is not already in Intacct**

1. Call `intacct-get-contact` filtered by `email`. If a contact is found, call `intacct-get-customer` filtered by `customer-name` = its `company-name`.
2. If the store customer has a `company`, call `intacct-get-customer` filtered by `customer-name.contains` with it.
3. If `{customer-id}` was given, call `intacct-get-customer` filtered by `customer-id` with it.

If any of these finds a customer that looks like the same person or business, show it and stop. Do not create a duplicate. If the requested customer ID is already taken, say so and stop.

**Step 3: Confirm**

Show the customer to be created:

* name: the company, or first and last name if there is no company
* print-as: the same as name
* email, phone, city, and state from the province
* status: active
* customer-id: the one given, or "assigned by Intacct"

Ask the user to confirm or correct the values. Do not continue without an explicit yes.

**Step 4: Create and verify**

Call `intacct-create-customer` with the confirmed values. Take `customer-id` and `record-number` from the result and call `intacct-get-customer` filtered by that `customer-id` to confirm it exists. Report the new customer-id and record number.

**Rules & Guidelines:**

* `mailchimp-get-customer` is on the mailchimp server. `intacct-get-contact`, `intacct-get-customer` and `intacct-create-customer` are on the intacct server.
* The Mailchimp `customer-id` is the store's own id. Never pass it to Intacct as the customer ID.
* The only write allowed is one call to `intacct-create-customer`, after confirmation. Do NOT call `intacct-update-customer`, `intacct-create-contact`, `intacct-create-order-entry-document`, `mailchimp-update-customer` or any other create or update tool on either server.

**Validation:**

* If `intacct-create-customer` fails, report the error as returned and do not retry with different values without asking.
* Leave a field blank rather than guess it.