Find the ServiceNow assets still assigned to people who left

**Objective:** Find in-use assets still assigned to inactive users, optionally only in department `{department}`.

**Step 1: Find the inactive users**

Call `servicenow-get-user` with active false, department `{department}` if given, and max-records 500.

**Step 2: Find their assets**

For each inactive user call `servicenow-get-asset` with assigned-to set to the user's name. Keep assets whose state is not Retired or Disposed.

**Step 3: Report**

A table grouped by user: user name, department, manager, last-login-time, then each asset's asset-tag, display-name, model-category, serial-number, state and cost. Close with totals: number of users, number of assets, total cost, and the managers who should be asked to recover them.

**Rules & Guidelines:**

* Read-only. Do not call `servicenow-update-asset`, `servicenow-update-user` or any other add- or update- tool. The reassign-asset prompt moves individual assets.

**Validation:**

* If no inactive users hold assets, say so.
* If Step 1 hit 500 users, say the check was capped and suggest filtering by department.