Add a modal to show today's due repetitions for a queue.

Use case: if you use an incremental writing queue as a task list, you could use it to show the tasks you need to get done today so you can add them in to your calendar / plan.

No files, tests, or entry points are named. Start by locating the queue interface and how due repetitions are represented, then define the modal's scope from the use case. Done means a queue can show its repetitions due today in a modal for calendar or planning.

Written by the indexing model from the issue text.