See every overdue BugHerd task, grouped by owner

**Objective:** Find open BugHerd tasks that are past their due date, for the project `{project-name}` and the assignee `{assignee-name}` when given (all projects and all assignees when empty), and say what should happen to each.

**Step 1: Narrow the scope**

* If `{project-name}` is given, call `bugherd-get-projects` with `name.contains` and take its project-id. If several match, list them and stop.
* If `{assignee-name}` is given, call `bugherd-get-users` with `display-name.contains` and take the user-id. If several match, list them and stop.

**Step 2: Read overdue tasks**

Call `bugherd-get-tasks` with `due-date.to` set to yesterday's date, plus `project-id` and `assignee` (the user-id) when you resolved them. Set `max-records` to 200. Drop tasks whose status is done or closed.

**Step 3: Report**

Group by assignee (put unassigned tasks in their own group). For each task show task number, title, project name, severity, due date and days overdue. Order each group by severity, then by days overdue. End with one line per assignee suggesting the next step (re-plan due dates, reassign, or escalate).

**Rules & Guidelines:**

* Do not call any write tool: `bugherd-add-task`, `bugherd-add-feedback`, `bugherd-update-task`, `bugherd-move-task`, `bugherd-add-comment`, `bugherd-add-attachment-from-url`, `bugherd-add-project`, `bugherd-update-project`, `bugherd-add-project-member`, `bugherd-add-guest-to-project`. This prompt is read-only.
* A task with no due date is never overdue; leave it out.

**Validation:**

* If nothing is overdue, say so plainly; that is a good result.