enhanced list move/merge/split

> Single `POST /lists/id/bulk` (or merge)
>
> Options:
> - merge-into: list ID to merge split cards into, default could be a new list... Or just require consumer to create first
> - delete: bool - delete this list after the merge...or require consumer...
> - some kind of before or after selector to essentially split the list
> - may also want a category selector

_Originally posted by @ctengel in [#93](https://github.com/ctengel/taskmaster/issues/93#issuecomment-3407756150)_

MVP had only basic API: source and destination list ids

prob do this in conj with #98

also may want way to pick where in new list the stuff goes