Hand over a rep's open HubSpot tasks in one pass

**Objective:** Reassign every open task assigned to `{from-assignee}` to the HubSpot owner `{to-owner-id}`, optionally only tasks due before `{due-before}`.

**Step 1: Check the new owner**

`{to-owner-id}` must be a numeric HubSpot owner ID. If it is not a number, ask for the owner ID and stop. Call `hubspot-get-users` with `record-id` = `{to-owner-id}` and, if that returns a user, show their name and email; if it returns nothing, warn that the ID could not be matched to a user and ask whether to continue.

**Step 2: Find the tasks**

Call `hubspot-get-tasks` with `assigned-to` = `{from-assignee}`, `max-records` = 100, and `due-date.to` = `{due-before}` when given. Keep only tasks whose `task-status` is not COMPLETED. If none remain, say so and stop.

**Step 3: Confirm**

Show the count and a table: title, due date, priority, status, contact email. State the old and new owner. Wait for an explicit yes.

**Step 4: Reassign**

Call `hubspot-update-task` once per task with `id` = its record-id and `owner-id` = `{to-owner-id}`. Change nothing else.

**Step 5: Report**

Report how many moved and list any that failed with the error. If the first two calls fail on `owner-id`, stop and tell the user the ID is probably not a valid owner ID.

**Rules & Guidelines:**

* Only `hubspot-update-task` may write, once per task, after Step 3.
* Do NOT call any other write tool: no other hubspot-add, hubspot-update, hubspot-rename, hubspot-remove, hubspot-subscribe, hubspot-unsubscribe or hubspot-import tool.
* Never reassign completed tasks.

**Validation:**

* If more than 100 tasks match, reassign the first 100, then tell the user to run the prompt again.
* If `{from-assignee}` matches more than one person, list them and stop.