Add new webinar attendees to Capsule CRM without duplicates

**Objective:** For the webinar `{webinar}` (on `{webinar-date}` if given), create a Capsule CRM person for each attendee who is not already in Capsule, owned by `{owner}` if given. Confirm before writing.

**Step 1: Find the webinar on GoTo Webinar**

Call `goto-webinar-get-webinar` with `webinar-name.contains` set to `{webinar}` (or `webinar-key` if `{webinar}` is a numeric key). If `{webinar-date}` is given, also set `date.from` and `date.to` to that date. If more than one webinar matches, list each with its name, date and webinar key and stop. If none matches, say so and stop. Keep its `webinar-key`, name and date.

**Step 2: Read the attendees**

Call `goto-webinar-get-attendee` with that `webinar-key`, group rows by email and keep `first-name`, `last-name`, `email` and total minutes attended. Drop rows with no email. If nobody attended, say so and stop.

**Step 3: Find who Capsule does not know**

Match each email to Capsule CRM by calling `capsule-crm-get-party` with `email` set to it. Compare emails case-insensitively; if the exact value finds nothing, retry once in lower case. A person can have several emails in Capsule and the filter may only see one of them, so treat no match as "not found by email", never as proof they are not a contact.

Also call `capsule-crm-get-party` with `name` set to "<first-name> <last-name>". If that finds a person with a different email, do not create them; list them as "possible duplicate" instead. Keep only attendees with no match by email and no match by name.

**Step 4: Resolve the owner**

If `{owner}` is given, call `capsule-crm-get-user` with `name.contains` set to it. If it matches exactly one user, use their `user-id` as `owner-id`. If it matches none or several, list them and stop. If `{owner}` is blank, leave `owner-id` out.

**Step 5: Confirm the plan**

List each person to create: first name, last name, email, minutes attended, owner. List the possible duplicates separately. Show the plan as a table and ask the user to confirm. Do not write anything until they say yes. If they remove rows, drop those rows.

**Step 6: Write and report**

For each confirmed row, call `capsule-crm-add-party` once with `type` set to a person, `first-name`, `last-name`, `email` and `owner-id` if resolved. Then report: people created, possible duplicates skipped, attendees already in Capsule, and any write that failed with its error.

**Rules & Guidelines:**

* `capsule-crm-*` tools are on the capsule-crm server; `goto-webinar-*` tools are on the goto-webinar server. If either set is missing, say which server is not connected and stop.
* The only write tool this prompt may call is `capsule-crm-add-party`, once per confirmed person. Do NOT call `capsule-crm-update-party`, `capsule-crm-add-note`, `capsule-crm-add-opportunity`, `goto-webinar-add-registrant` or `goto-webinar-delete-registrant`.
* Create people only, never organizations; GoTo Webinar attendees carry no company.
* Registrants who did not attend are not included.

**Validation:**

* If an attendee has no first or last name, use the part of the email before the @ as the first name and say so in the plan.
* If a write fails, carry on with the rest and report the failures at the end.