Add a Nutshell contact to a Mailchimp audience, safely

**Objective:** Subscribe the Nutshell contact matching `{contact-name}` to the Mailchimp list named `{list-name}`, only after the user confirms.

**Step 1: Find the contact in Nutshell**

Call `nutshell-get-contact` (Nutshell server) with `name.contains` set to `{contact-name}`. If more than one matches, list them and stop. If none, stop. Keep name and emails. If there is no email, stop and say the contact cannot be added. If there are several emails, ask which one to use.

**Step 2: Check Mailchimp first**

Call `mailchimp-get-list` (Mailchimp server) with `name` set to `{list-name}` to get the list-id. If it does not match exactly one list, show the candidates and stop. Then call `mailchimp-get-list-member` with `email` set to the chosen email and check the result for that list-name. If already subscribed, report that and stop. If unsubscribed or cleaned, report that and stop: never re-subscribe someone who opted out. Compare case-insensitively.

**Step 3: Confirm, then add**

Show the user the first-name, last-name, email, list name and the status `subscribed`, and ask for explicit confirmation. Only after a clear yes, call `mailchimp-add-list-member` (Mailchimp server) with list-id, email-address, first-name, last-name and status `subscribed`. Then call `mailchimp-get-list-member` again with the email to confirm it landed.

**Step 4: Report**

State what was added (or why nothing was), with the list and the confirmed status.

**Rules & Guidelines:**

* `mailchimp-add-list-member` is the only write tool and may be called once, after confirmation. Never call `mailchimp-update-list-member`, any delete or update tool on Nutshell, or `nutshell-add-person`.
* Only add contacts who are not already members; never override an opt-out.

**Validation:**

* No confirmation, no write.
* If the confirming read finds nothing, report the add as unverified.