Find AvaTax vendors that are not ready for year end

**Objective:** Review vendors for `{company}` (all if omitted) and flag those with missing tax data or no recent activity, using `{dormant-days}` days (default 365) as the dormancy limit.

**Step 1: Read vendors**

Call `avalara-avatax-get-vendor` with `company` if given. Read `vendor-code`, `name`, `taxpayer-id-number`, `email-address`, `country`, `region`, `postal-code`, `last-transaction`.

**Step 2: Check**

* Missing `taxpayer-id-number`.
* Missing `email-address` or address fields.
* `last-transaction` older than `{dormant-days}` days or empty (dormant).
* Duplicate vendors: the same `name` or `taxpayer-id-number` under different `vendor-code` values.

**Step 3: Report**

Counts per issue, then a list of vendors per issue with the vendor-code, name and detail. Put missing taxpayer IDs first.

**Validation:**

* If `{dormant-days}` is not a positive number use 365 and say so.
* If no vendors return, say so.

**Rules & Guidelines:**

* This prompt is read-only. Call only the `avalara-avatax-get-*` tools named above. Never call any avalara-avatax tool that adds, updates, deletes, commits, uncommits, voids, unvoids, adjusts, refunds, locks, settles or creates anything.
* Report what the data shows. Do not guess values the tools did not return, and say so when a field came back empty.
* Use `max-records` to keep each read small, and say when a result may be truncated by it.