Enrol Sage Intacct customers in a Drip campaign without opt-outs

**Objective:** Subscribe the email contacts of active Intacct customers, filtered by customer type `{customer-type}` and state `{state}` when given, to the Drip email series campaign `{campaign}` (an ID or name). Skip anyone unsubscribed or already in the campaign. Nothing is written until the user confirms.

**Step 1: Find the campaign in Drip**

Call `drip-get-campaign` with `campaign-id` set to `{campaign}`, or if nothing comes back with `name.contains`. It must match exactly one campaign; otherwise list the matches and stop. If its status is not active, warn that people added will not receive emails until it is activated, and do not activate it.

**Step 2: Select customers in Intacct**

Call `intacct-get-customer` with `status` active, `customer-type` and `state` when given, and `max-records` 200. If exactly 200 come back, say the selection was capped. If none come back, say so and stop.

**Step 3: Collect their email addresses**

Take each customer's email, and call `intacct-get-contact` with `company-name` set to the customer-name for its contacts' emails. Drop blanks, values without an @, and case-insensitive duplicates.

**Step 4: Check each email in Drip**

Call `drip-get-subscriber` with `email`. If the subscriber's status is unsubscribed, skip the email. Otherwise call `drip-get-campaign-subscriber` with `email` and `campaign-id`; if it returns a row, skip the email as already enrolled. Emails with no Drip subscriber are added as new people.

**Step 5: Confirm**

Show a table: customer-name, email, Drip status (or New to Drip), action (Enrol / Skip with reason). State how many people will be enrolled and how many of them Drip will create as new subscribers. Ask the user to confirm and do not continue without an explicit yes.

**Step 6: Enrol and verify**

For each email marked Enrol, call `drip-add-subscriber-to-campaign` with `campaign_id` set to the campaign-id and `email`. Then call `drip-get-campaign-subscriber` with `campaign-id` and confirm each one is listed. Report enrolled, skipped and failed counts with every failure's error.

**Rules & Guidelines:**

* `intacct-get-customer` and `intacct-get-contact` are on the intacct server. `drip-get-campaign`, `drip-get-subscriber`, `drip-get-campaign-subscriber` and `drip-add-subscriber-to-campaign` are on the drip server.
* The only write is `drip-add-subscriber-to-campaign` on the drip server, once per email, after confirmation.
* Do not call `drip-activate-campaign`, `drip-add-subscriber`, `drip-update-subscriber`, `drip-remove-subscriber-from-campaign`, `intacct-update-customer`, `intacct-update-contact` or any other write tool on either server.

**Validation:**

* Never enrol an unsubscribed person, even if the user asks for everyone.
* If one call fails, record it and carry on with the rest.