NATS on Deno Deploy

This is just an idea, but: it would be amazing to have NATS integrated into Deno Deploy.

Both are beautifully simple pieces of software and platforms, I think they would work great together.

Unfortunately right now it is virtually impossible to use them together without either a dedicated server or a wasteful cron that wakes a process regularly.

Deno Deploy has Queues, but as far as I understand they are nowhere near as versatile: no at-most-once delivery, no ability to have multiple consumers and no replay.

It would be amazing if NATS was a first class citizen in Deno Deploy. It is not strictly required because a third party SaaS could provide the same waking service by listening to NATS messages, buffering them and sending requests to a Deno service. But using all three together would be significantly less straightforward compared to just having the Deno service subscribe to NATS subjects/streams directly with an API similar to `listenQueue`.

No files, tests, or entry points are identified in the issue. First clarify the proposed Deno Deploy and NATS integration, including subscription behavior and delivery guarantees; done would mean a concrete, maintainable design that supports the requested consumer and replay semantics.

Written by the indexing model from the issue text.