Export Tasks

Export tasks as CSV or JSON.

Query params: format: csv or json (default json). limit: Optional max number of tasks to return. Pushed into TaskStore.list_tasks so large stores no longer materialise the whole table (issue #1728 finding 3). offset: Optional number of tasks to skip before returning rows.

The export is a whole-store read, so it narrows to the caller's tenant scope the same way the paginated task list does. The scope is pushed into list_tasks rather than applied to the returned rows so that it is limit/offset that page through the caller's own tasks: filtering after the slice would page through every tenant's and return short pages.