Follow up unpaid Shopify draft orders through Drip

**Objective:** Tag in Drip, with `{tag}` (default open-draft-order), every subscribed customer who has an open Shopify draft order created on or after `{since-date}` (default 14 days ago).

**Step 1: List open draft orders**

Call `shopify-get-draft-order` with `status` set to open and `created-at.from` set to `{since-date}` (or 14 days before today, YYYY-MM-DD). Keep draft orders with an email and no order-id (not yet converted). Group by email, keeping the draft order name, total-price, currency and created-at.

**Step 2: Match them in Drip**

For each distinct email, call `drip-get-subscriber` with `email` set to it. Keep only subscribers whose status is active. Skip anyone already tagged `{tag}` (or open-draft-order).

**Step 3: Confirm**

Show the list to tag (email, draft order names, total value) and counts of customers skipped because they are absent from Drip, unsubscribed or already tagged. Ask the user to confirm. Do not continue without a clear yes.

**Step 4: Tag and report**

For each confirmed subscriber, call `drip-add-subscriber-tag` with `email` and `tag` set to `{tag}` (or open-draft-order). Report tagged, failed and skipped counts.

**Rules & Guidelines:**

* `shopify-get-draft-order` is on the shopify server; `drip-get-subscriber` and `drip-add-subscriber-tag` are on the drip server.
* `drip-add-subscriber-tag` is the only tool that may write, and only after Step 3's confirmation.
* Do NOT call `drip-add-subscriber`, `drip-add-subscriber-to-campaign` or `drip-start-subscriber-workflow`. Never create a Drip subscriber for someone who is not already one.

**Validation:**

* If no open draft orders come back, say so and stop.
* If `status` set to open returns nothing but draft orders exist in the window, retry without `status` and keep those whose status reads as open, and say you did so.
* Compare emails case-insensitively.