Enroll the right DonorPerfect donors in a Drip series once

**Objective:** Subscribe DonorPerfect donors to the Drip email series campaign `{campaign}`, limited to donors whose gift total is at least `{gift-total-min}` (default 0) and, if given, whose donor type is `{donor-type}` (default all types). Enroll at most 50 donors per run.

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

Call `drip-get-campaign` with `name.contains` set to `{campaign}`, or with `campaign-id` if `{campaign}` is numeric. If more than one campaign matches, list them and stop. If the campaign's status is not active, warn the user that enrolled people will not be emailed until it is activated.

**Step 2: List the donors**

Call `donorperfect-get-donor` with `gift-total.min` and, when supplied, `donor-type`, and `max-records` set to 50. Drop donors with a blank email.

**Step 3: Remove people already enrolled or unsubscribed**

Call `drip-get-campaign-subscriber` with `campaign-id` set to the campaign's id and drop donors whose email is already in it. For each remaining donor, call `drip-get-subscriber` with their email and drop anyone whose status is unsubscribed.

**Step 4: Confirm**

Show the campaign and the donors to enroll (name, email, gift total), plus counts of those dropped and why. Ask the user to confirm. Do not continue without an explicit yes.

**Step 5: Enroll and confirm**

For each confirmed donor, call `drip-add-subscriber-to-campaign` with `campaign_id` set to the campaign's id and `email` set to the donor's email. Then call `drip-get-campaign-subscriber` for the campaign once more and report enrolled, failed (with reasons) and skipped counts.

**Rules & Guidelines:**

* `donorperfect-get-donor` is on the donorperfect server. `drip-get-campaign`, `drip-get-campaign-subscriber`, `drip-get-subscriber` and `drip-add-subscriber-to-campaign` are on the drip server.
* The only write this prompt may make is `drip-add-subscriber-to-campaign`, on the drip server, after confirmation in Step 4. Note that Drip creates the subscriber if they do not exist yet; say so in the confirmation.
* Do not call `drip-activate-campaign`, `drip-update-subscriber` or any DonorPerfect save tool.
* Never re-subscribe someone whose Drip status is unsubscribed.

**Validation:**

* If no donor matches the filters, say so and stop.
* If every matching donor is already enrolled, say so; nothing needs to change.