Catch duplicate Sage Intacct bills before they are paid twice

**Objective:** Find bills entered more than once over the last {lookback-days} days (default 90), for vendors whose name contains `{vendor-name}` (blank means all vendors), and say which duplicates have already been paid.

**Step 1: Pull the bills**

Call `intacct-get-bill` with `bill-date.from` set to the start of the window and `max-records` 2000, adding `vendor-name.contains` when a vendor name was given. Ignore bills with a `total-amount` of zero.

**Step 2: Find candidate duplicates**

Compare the bills in these passes, strongest first:

* High: same `vendor-id` and the same `bill-number` once case, spaces, punctuation and leading zeros are ignored.
* Medium: same `vendor-id` and same `total-amount`, with `bill-date` values no more than 7 days apart.
* Medium: same `vendor-id`, same `total-amount`, and the same `reference-number` or `description`.
* Medium: different `vendor-id` but a near-identical `vendor-name`, with the same `total-amount` and `bill-number`. This also points to a duplicate vendor record.

Before reporting a medium candidate, rule out recurring charges. Bills of the same amount from the same vendor about a month apart are usually rent or subscriptions. Call `intacct-get-recurring-bill` with the `vendor-id`; if an active template has that amount, drop the pair.

**Step 3: Check the evidence**

For each remaining candidate:

* Call `intacct-get-bill-line` with each bill's `record-number` as `bill-record-number`. Matching accounts and amounts strengthen the match; different accounts weaken it.
* Call `intacct-get-ap-payment-detail` with each bill's `record-number` as `bill-record-number`. Record whether each bill was paid, with its `payment-date` and `payment-amount`.

**Step 4: Report**

Sort candidates paid twice first, then high, then medium. One row per candidate group: confidence, vendor, bill numbers, bill dates, amounts, states, paid (both, one or neither), payment dates, and why they matched.

Then the total exposure: the amount already paid twice, and the amount that would be paid twice if the open copies went through.

Recommend, per group: stop the unpaid copy before the next payment run, or ask the vendor for a refund or credit where both were paid.

**Rules & Guidelines:**

* This prompt is read-only. No tool on this server voids or reverses a bill. Do not call `intacct-update-vendor`, `intacct-create-recurring-bill` or any other create or update tool.
* Present every group as a candidate to review, never as a confirmed duplicate.
* Pass dates as YYYY-MM-DD. If the user names an Intacct company, pass it as `company` on every call.

**Validation:**

* If no bills come back, say so and stop.
* If the bill call returns exactly `max-records` rows, say the sweep is incomplete and suggest a shorter window or a vendor filter.
* If nothing matches, say no duplicates were found and give the number of bills checked.