Deleting envelopes is a lot more dangerous if you can't see which envelopes are there to be deleted. Implement a GET /content/ endpoint to list known content IDs.
[x] First pass: list absolutely everything.
[x] Filter by a prefix.
[x] Pagination, consistently with the way it works for /search.
Deleting envelopes is a lot more dangerous if you can't see which envelopes are there to be deleted. Implement a
GET /content/endpoint to list known content IDs./search.